The probe is not immediately destroyed, so that's probably a good thing.

The system is sparse, but not uninhabited. Two gas giants on the outer perimeter with a handful of moons apiece, three small and rocky worlds closer to the star, lambent and red. A scattering of satellites whip around the star in close orbit, and there are industrial activities on the second and fouth planets.

The scientists adjust the probe's scanners and cameras to look at the fourth planet.

They check for technology-level.  Any ships, artificial satellites, or space stations in orbit?

The main installation seems like a storage facility or refinery. Skimmers descend into the cloudy depths and return to discharge their cargo into the massive tanks attached to all sides of the hexagonal station.

And the second planet?

Operations here are focused on research rather than exploitation, with an extensive sensor net across all three continents and their varied biomes.

Based on their findings, the scientists are currently guessing these machines are the work of some civilization originating outside of the system.  

They check for radio waves, hoping to detect a communication frequency to make contact through.

There are no radio signals detectable from the edge of the system.

There are, however, three ships in close formation approaching the portal. Their design is arcane and angular, but they are clearly armed.

The probe sends out a pattern of prime numbers over frequencies that Murune most commonly uses for space, standing still in front of the portal.

The ships pull to a relative stop a respectable distance away, and there's a few hours' pause as the probe and the portal are thoroughly scanned.

The probe is mostly metal, and seems to work through understandable technological means.  Most of its mass is made of a large antenna dish and other sensors that seem to have been made for deep space viewing.  It tries the prime number sequence again every 30 minutes, and noninvasively scans the ships.

The portal is very much magic.  The torus around the edges is only a few feet thick, a narrow band of white around the circle of space showing different stars.  It gives off the same readings as come through from the space on the other side.  

A single unarmed research ship is on the other side.  Owlida design with smooth curves and lines of pastel colors.

Once the corvettes' scans are finished, they preempt the next transmission of numbers with their own, repeating it back to the probe.

Communication!  Sort of.  None of the races in Murune had needed to first communicate through separate and likely-vastly-different computer systems, so they're running on the best ideas their science fiction writers have come up with.  

They begin sending a steady stream of text written in their simplest language, including things like the periodic table which they hope will be easy to recognize.  Presumably a civilization that has both FTL ships and access to lots of other star systems will have better translation than they do, though the research ship does prepare the computers to process anything sent back.  

The other side transmits a reciprocal set of data.

About a day later, a new ship shimmers into being within view of the portal. About as big as the others, but with less obvious armament and two forward-swept arms enclosing a geodesic sphere that glows with inner radiance and seems to be floating unattached to the rest of the ship's structure. Shortly after its appearance, the transmissions become more detailed, and are accompanied by a translation in the portalmakers' language.

With a translation in their computers, the ship composes a message.

"This is the research vessel Dewgather, from the star system Murune.  We are on a mission of exploration and scientific discovery."

A reply comes back: "Research vessel Dewgather, know that you stand on the threshold of the sovereign territory of the Virene Imperium and all these stars are claimed in the name of the Empress's divine majesty."

"Our empire would be interested in opening diplomatic communication between our respective civilizations.  We have received authorization to extend an invitation for a diplomatic ship from the Virene Imperium into the Murune system.  The Kiarasa representative of our crew is also capable of acting as a diplomat, and has been granted the authority to make short-term agreements under the authority of the Champion of Murune.  

"We can also call for a tow-ship to move our portal, if you'd prefer to have it elsewhere.  The current location was placed blindly, as there was no way to determine what would be on the other side."

One of the corvettes peels off and makes for the mining station.

"The Empress has decreed that she will attend this contact in person. The Stooping Falcon goes now to fetch her. She will lead the delegation to your star while an escort assembles here."

"Murune will be honored to host your Empress.

"What atmosphere and temperature would be best for the species making up the delegation?"

Such scientific data can be provided.

Murune prepares.  The champion and high priest make their ways to the palace of Murune's Empress - the high priest by shuttle, the champion by a long sequence of portals and subway systems.  Minor atmospheric changes are made to the main hall, and it's fully sterilized of any potentially dangerous microorganisms.  Not that much can go wrong with a god and a biokinetic on hand, but it wouldn't do to look sloppy.  There's a plan to clear a wide path between MuurKari and the portal of normal traffic.  Police patrols in the area are increased.  

On the other side of the portal, the corvette returns and docks with the science ship briefly. After it breaks off, the science ship powers up its engines and begins to drift gently through the portal.

The ship passes through the portal without incident and are now in Murune's borders. 

Dewgather greets them.  "Our Empress invites you to the Imperial Palace."  They provide a map.  "The portal is about 5000 au away from MuurKari, which is a 13 hour trip via lightwarp.  We aren't familiar with your method of FTL, however."

"Our FTL only functions at the edge of a stellar gravity well. Intra-system travel is slower than light. It will take us approximately five days to cover this distance."

"We haven't been given permission to leave the portal area, but we can request a ship be diverted to pull you in their lightwarp bubble if you'd prefer.  The nearest ship is four hours away."

"That will do."

Four hours later, a ship arrives and announces itself as the Marchseam.  It's an older model than the newly-commissioned Dewgather, stubby and painted in elaborate swirling patterns of teal and ice blue.  

The ship wastes no time in arranging itself beneath the Virene Ship, then pulling it forward towards the inner system.  

They gather as much data as they can about the trip.

Murune is a star with 3 planets and a wide asteroid belt, inhabited but not crowded.  There are around 20 billion people scattered across planets, moons, and space stations.  Many ships are shuttling people or cargo between stations or pulling objects from the outer asteroid belt or oort cloud.  No ships are traveling to other stars, and the portal between their two universes seems to be the only one that currently exists.

From the edge in, the closest planet is the gas giant Netarin.  It has dozens of smaller moons home to mining stations, and four large moons that are clearly impossible.  Breathable nitrogen/oxygen atmospheres with liquid water far past the point where they should have been frozen.  The smallest should have been too light to keep its atmosphere.  The sandy one is orbiting slow enough that it should have fallen into the gas giant.  Visible cities dot these moons, having been inhabited for centuries.

The middle planet Tle is a rocky planet in the zone where it should have liquid water, and does.  Breathable atmosphere, saltwater oceans, and green-covered continents.  Ships cloud around the large stations on top of its four space elevators.  

The Marchseam slows them down over Muurkari, a rocky airless tidally-locked planet closest to the star.  Most of the surface is dotted with solar farms, and a ring of arcologies around the twilight band.  From the map and information offered, there is supposedly a large population in tunnels beneath the planet's surface as well.  There is an especially palatial structure right on the north pole, where they'd been directed.  A massive translucent dome and sprawling spires of bronze in elaborate and artistic shapes.

Is there a landing site that can accomodate the ship?

Word of their arrival has preceded them.  They are directed through a massive airlock next to the dome itself, rather than try to figure out how to hook a ship with different door designs into the standardized airless dock system.  Like the rest of the palace, it is made entirely of bronze and a tinted glasslike material.

A simple enough solution.

The ship maneuvers gracefully through the door to touch down with a soft hiss.

Once the room has atmosphere, three Murune natives step into the room and wait for the visitors to disembark.

They are led by an extremely tall human.  The fashion for Murune formal wear this century is long skirts for all genders, with metallic threads and gems embroidered onto the fabric to match elaborate jewelry.  His is particularly ornate to signify rank, almost looking like chainmail.

Behind him stands two much smaller species.  First is a multicolored 4-winged variant with a head like a claw hammer and four faceted eyes.  Beside it is an even smaller feathered biped with a vestigial pair of wings on the shoulders of an otherwise humanoid body plan.  Or, humanoid as far as can be seen - the long skirt hides what their legs look like.  

From the ship extends a ramp, and down it descend three humanoid figures. The two leading wear sleek dark body armor with no visible insignia or sign of rank and carry heavy rifles at a sharp angle across their chests. They come to a snappy halt at the end of the ramp.

The third figures walks down sedately behind them. A woman in finely tailored robes, hood thrown back to expose her face, not quite so tall as the leader of the other delegation. She reaches the bottom of the ramp and takes one step beyond her bodyguards, regarding the reception committee steadily.

The Murune group performs bow-like gestures, and the human steps forward.  As he speaks, his words are overlaid with a second voice speaking in every listener's native language.  

"I am Raen'Vine, Champion of the Murune System.  I am in command of all of Murune's foreign affairs.  These are my head diplomat and master of exploration, respectively.

"We're here to lead you to Empress Hirune's audience chamber.  Beyond that, I will also likely be the main point of contact between our civilizations, as Hirune prefers to take a hands-off approach to rule in most circumstances."

"Raen'vine. I am the Empress of Vir, Lightbringer and Breaker of the Cycle, the goddess beyond time." She speaks the language flawlessly and without accent. "Bring me, then, to your leader."

"Right this way."

He leads her through a short hallway, then into the dome itself.

Empress Hirune's preferred physical manifestation is the centerpoint of the massive room.  Rather than mimic one of the species of her domain, she has continued the tradition of her kind and created something unique and building-sized.

There's a raised dais close to the entrance from the dock, and Ara'Vine walks up to stand to one side.  Opposite him is an old kiarasa with something elaborately embroidered trailing down to the floor around its perch.  The center is the obvious place for the visiting Empress to stand.

She takes her place there, flanked by her bodyguards.

She essays a light psychic probe, seeking to ascertain the shape of the mind before her.

Hirune permits this, curious, and sends through information as a greeting.

A zoenshoeth is a sapient component of the physics of this universe, cycling potential the way that clouds cycle water back from the ocean to the land.  When entropy increases, that lost potential is moved to their layer of reality, where they can move it back as they wish.  As such, this universe is quite old, having gone through many cycles of heat death and recreation, cycles where they maintained the stars for trillions of trillions of years before letting things fade.  

Hirune in particular is very young, only 60 years as the mortals here count them.  She formed as the concept of this part of space being composed of planet-sized parts started instead considering itself as being composed of a solar system.  The permission for the mortals to travel between the planets was the mechanism her parents used to contemplate merging.  Hirune has chosen to rule them personally for a few centuries as she settles, rather than leaving them alone as most others do.

The 2-light-year-radius barrier around this system is a decision between her and the zoenshoeth of other star systems, who prefer not to merge.  However, there's no risk of merging with another universe, so when the mortals began getting sad that they'd reached the edges, she opened up a portal to another universe for them.

The mortals have called so many different things 'gods' and she's curious to learn what definition is being used for the visiting Empress of Vir.

She is called a god because she is the guide, protector, inspiration, and example to her people. She is the strongest human psionic there will ever be. She broke free of a time loop that a malevolent entity had trapped her species in so that it could feed on them. She awakened others to their psionic potential. She shepherded her people from stone forts to sprawl across the the galaxy. Her subjects worship her. That is why she is a god.

All this she conveys without speaking.

A valid definition, though Hirune supposes any definition that is being used and understood by people is.  That is how language works.  Speaking of which, they should probably speak aloud for the sake of her Champion and High Priest.

"Tell us about your universe.  Are there many different kinds of people there?"

"There are eleven Great Powers at present, which is to say species that control multiple systems and habitable planets, and that have the resources to defend those claims. In addition to these, there are some few dozen others known to the galactic community at large who are either migratory remnant populations, hostile unaligneds, uninterested in expansion, or below the technology level required for spaceflight. My empire is composed primarily of humans, of which I am one, and smaller populations of srrseke, furred mammals averaging half the size of a human, and ootaanii, aquatic molluscoids adapted to extreme pressure."

"We have several here, though the exact number is a matter of some debate on what counts as a 'species'.  As few as 5, to as many as 14.  I'm sure the humans of Murune will be very interested in learning how similar yours are to ours.  It isn't surprising that a humanoid form would evolve twice - they were the one species to evolve naturally here while the Tle zoenshoeth was focused elsewhere - but the exactness is astounding."

"The other species present here were created by others of your kind?"

"Yes.  Zoenshoeth tend to create life in their domains, if the domain is remotely suited for it or can be made so.  Physical life is aesthetically pleasing for us, and sapient ones are moreso, with their cities, roads, and ships."  

"What are the other species here like?"

"The six humanoids are humans, fishfolk, merfolk, mersol, ray-solon, and claw-solon.  Humans evolved naturally but were used as a base to create others.  Their interbreeding acts like three codominant alleles, meaning the pure-breeds will always breed true, the hybrids will regularly produce throwbacks, and they don't hybridize into further fractions.  Ray Solon are tall and have 6 tentacles in place of arms.  Very prosocial and community-minded, and make up most of the inhabitants of MuurKari.  Their hybrid with humans are the claw solon, which trade in 2 pairs of tentacles for arms.  Merfolk are the other pure-breed, with fish-like tails in place of legs, and gills with no lungs.  They inhabit the saltwater oceans of the system, and are otherwise pretty similar to humans.  Fishfolk have human body plans but shorter legs, both gills and lungs, and often have scaly patches.  Mersol (solon-merfolk hybrid) are very rare, but have humanoid upper bodies with 8 tentacles in place of legs. 

"The other main group is the Saurians, composed of two pure-breeds (the shoth and kiarasa) plus their sterile hybrid dracona.  Kiarasa, like the chief ambassador and the High Priest, are experts at administration and leadership.  Shoth are the opposite - mentally dull but physically powerful.  Dracona are a middle ground that is fairly human-like in their abilities, and are known as skilled craftsmen.

"Tripods have three arms and three legs, and an unfortunate high reproductive drive which once caused war.  This has been solved with the creation of a genetically-engineered symbiote which can imitate fetuses within the queens and prevent overpopulation.  Besides that, they are usually model citizens as long as they're permitted to spread out within other species' cities rather than live close enough to their own kind to have to smell rival queens' pheromones.

"Owlida were the first created species, and include the Master of Exploration, there.  Small, peaceful, and brilliant at technology.  They were originally created to inhabit the Netarin moons, but the zoenshoeth ruling that planet eventually grew tired of them and replaced them with the tripods.  That they survived at all is due to the zoenshoeth of Tle, who collected an arcology full of them and squirreled them away in her zoo for extinct animals.  They were released along with the Saurians only a few hundred years ago.

"Dryads were the most recent species, created after humans nearly wiped themselves out 700 years ago, to preserve what they could of the cities and culture of the time.  They are plant-like, spending a long adolescent period as mobile saplings, using artificial chassis as skeletons to move their flexible branches against like muscles.  When they've grown too large to continue, they join large Groves composed of thousands of dryads who have merged into massive hive-minds which make up several cities in the tropical regions of Tle."

"Did your kind get bored often?"

"Our personalities vary.  As far as my own domain is concerned, there are no extinct sapients other than a few near-human hominids which wound up outcompeted through natural means during humanity's evolution.  If there had been anything worthwhile to collect, they would have been in The Vault along with the owlida."

"Do you often come across signs of extinct species in your universe?"

"Yes. The history of the galaxy is quite long, and life has arisen many times in a multitude of forms."

"You mentioned a malevolent entity which you had defeated.  Are such things common?"

"The Shroud is host to many demons, but very few on that scale."

"What is the Shroud?"

"The Shroud is the realm of psionics. It is a hidden realm or dimension composed of thoughts of every sentient being."

"Interesting.  We have the layers of reality where zoenshoeth reside, but nothing with thoughts and demons. 

"Is there a relation between psionic people and the Shroud?"

"Psionics are those who can consciously control their connection to the Shroud, and manipulate its energies to achieve effects in the physical world."

"How common are psionics?"

"The potential resides in all beings. I awaken everyone under my rule. Outside of such intervention, active control is much rarer. The natural rate of occurrence is on the order of one in one billion."

"Did you notice any drop in the available energy in the Shroud after this policy was enacted?"

"The Shroud does not obey ordinary conservation laws. 'Available energy' is not a meaningful concept."

"Fascinating.  Our world is ever-cycling and eternal, but what can be done at any given time without destroying what already exists is limited.  In a population of 13 billion sapients, less than a million of them have magic.  Much of the potential I choose to spend is on portals and maintenance of my parents' systems to keep the Netarin moons and MuurKari's caverns habitable.  My counterpart, who collects the lost potential of things I do in the same way that I get his, has decided to be stingy with returning things this eon.

"Assuming there are things our magic can do which psions can not, and a way to transfer potential or energy, I suspect we can have worthwhile trade."

"Perhaps. There is always cultural exchange, of course."

"Naturally.  Though, I take little interest in curating culture personally.  I choose to limit myself to maintaining a constitution of standard laws which all of the countries of my empire must follow, and letting the physical beings fill in the gaps for themselves."

"I would be interested in seeing more of your empire."

"That can be arranged.  I can send my Champion to escort you to whatever interests you.  He has been to most places of note, and as he is in charge of foreign relations for Murune it will be useful for him to understand your people better."

"This is acceptable."

Eh, fine.  He guesses he can do that.  

"May the meeting of our worlds be beneficial for everyone involved."