A few years ago, Deekin would have been very cavalier about this weird demiplane that just inserted itself into the Underdark, much as he was about basically everything. Times have changed, though; now Tynan is a factor, so instead of skipping merrily towards the bar, Deekin keeps his crossbow high and his stance low, even as the baby pokes his head out of his rucksack and babbles merrily.
...This place doesn't seem to be dangerous in any way.
This is intensely suspicious.
But after a quick casting of See Invisibility, a nip of Barkskin potion for Tynan, and a nice loud Curse Song in case someone's still hiding somewhere, Deekin feels comfortable enough to sit at the very polite bar and get free drinks. (Tynan gets some kind of strange black milk, which he obviously enjoys. Deekin gets something he thinks might be apple cider with a shot of cow blood, which is very nice even if it does kind of remind him of Tymofarrar.)
Deekin frowns thoughtfully. "Toril magic lots of stuff, but for some reason most of it for killing things. Deekin got three scrolls in bag for kill somebody with lightning but none for build a table? Deekin think that very strange, personally. And then song magic, not really magic but with songs Deekin make people strong and fast and good at things. And Enserric eat life force and Deekin got other weapons in bag with fire or ice power and stuff. Plus berries. Berries still for killing things though. Very strange."
"No, no, berries just help kill things. Look!"
Deekin pops a red berry into his mouth. His teeth and claws burst into flame, though heat doesn't radiate from them past a few inches. "Very helpful berries."
With an effort of will, the flames flicker out. Deekin continues, "Deekin think magic must be invented, at least wizard kinds. Sorcerers maybe just finding magic inside themselves or something, who know what bards doing, but Deekin know at least some spells for killing things named after wizard who made them, so."
"And wizards don't - I don't know. Make spells for summoning ration bars?"
"Oh, no, spell for that is very common. Deekin got bag of endless trail rations, taste like sawdust but very nutritious. But... one spell for food, six spells for killing with lightning. Deekin try to count how many ways to kill with lightning once, lose count after lots."
Deekin shakes his head quickly. "Oh, definitely not always lightning. Fire much more common. Ice common also. Sometimes acid. Every once in a while sound or searing holy light or raw force or concentrated essence of un-life."
"I remember one spell that created water in the foe's lungs," reminisces Enserric. "Some druid came up with it, of course. Druids are bastards."
"Drowning spell sound better than evaporate all water in body spell," notes Deekin. "That being wizard stuff."
Enserric sniffs. "The distinction is subtle, and perhaps unsuited to the reptilian brain."
"Honestly, evaporation sounds better to me than drowning. It's faster. Drowning takes time."
Deekin shrugs. "Hey, Deekin still use evaporate spell. Sometimes needing to kill lots of guys with swords at once. Just saying it not very nice."
"I think killing people is typically not considered very nice," says Callida, dry. "... How do you learn your magic?"
Deekin shrugs. "Deekin not learn magic properly, really. Old Master say normal way take years, maybe decades, and kobold lifespan not great. But Deekin have natural talent, so Old Master teach channeling dragon-style, so Deekin got couple of spells and can cast others from scrolls and wands and stuff, instead of cast all the spells but be old and have to go to battle with cane so Deekin not break hip."
Enserric coughs delicately. "If you wanted to learn magic yourself, as I assume was the actual point of that question, you would probably either need to come back with us to our world and find a teacher, or get a lot of books and resign yourself to occasionally being on fire until you're learned properly."
"When you say occasionally being on fire... How bad of a fire are we talking?" she wonders, seriously. "If it's just being on fire, well - that's actually not bad, I can work near bodies of water or fire suppressors, but if that's a stand in for other horrible things that could happen..."
"There are other horrible things, but they are for the most part less dramatically unpleasant than being on fire. The main problem is that if you do catch fire, something went wrong, and it's very difficult to actually figure out what when you're the one casting the spell, and further mistakes will generally set you on fire again. Or encase you in a thin layer of rock, or generate a cloud of butterflies, or turn your fingernails into wasps. Hence the reliance on apprenticeship."
"My fingernails into wasps. That sounds far more dramatically unpleasant than being on fire, being on fire can be quickly handled by various methods of dousing or smothering, wasps in place of fingernails is less so. Is there a guarantee I could get back to my, uh, world, after going with you?"
"Transformations of that kind are easily dispelled," Enserric says dismissively. "...though of course, without a mentor you would be unlikely to have access to dispelling magic," he admits.
"Deekin could teach to use dispelling wand," Deekin suggests. "Or harp, or cup, or sword. Lots of dispelling items. Easy fix, and mostly just taking space in Deekin inventory."
"As to whether you could return... I'm not certain. Does the bar know anything about it?"
Doors to Milliways cannot exactly be depended upon, but if she ever finds one, she can return to her world by entering the bar and opening the door back out; it always leads to one's home universe. Without a door, however, return could not be guaranteed without the intervention of Fharlanghn or an entity of greater power with domain over travel, such as the Lady of Pain.
Enserric sucks in a breath. "Implausible, then."
"Not, at the moment, uh. ... What can you tell me about how -" she peers at the other napkin, "Milliways works?
Milliways is a pocket dimension isolated from the rest of reality both spatially and temporally. While you are in Milliways and the door is closed, you experience time which does not pass in your own world, unless you have no intention of or are somehow incapable of ever returning to your own world, in which case time will resume. The same applies if you follow someone into their own universe, with occasional inconveniently arbitrary exceptions which do not apply if you remain in Milliways. I have no connection to or communication with the agent(s) of the door or the temporal effects; I cannot actually be certain agents for such exist, but evidence suggests that bargoers are selected for being 'interesting', which implies at least that a sophisticated algorithm is in place. At any rate, I am an agent only of the bar itself, as an interface for the purchase of food, drink, and near-arbitrary nonmagical objects and matter.
There is a pause. Which you are not. I just checked.
"Leave off Blackstaff's gibberish," Enserric recommends. "The man had some very funny ideas about the order in which one should teach the fundamentals. I mean, really, did he expect every apprentice to arrive on the scene knowing the precise ontological differences between deception via illusion and via enchantment? What an utter prick."
Your friend's argument is repeated in certain contemporary reviews of the book in question, Bar notes. Although most appear to be his own writing.
"Passionate feelings on the subject, eh? Well. Okay, Enserric, you were the wizard, what are some of the best books for it?"
"Well!"
Enserric does indeed have passionate feelings on the subject. He never personally published anything beyond a few treatises, but he was firmly entrenched in academia in life, and his expertise is not to be scoffed at.
Tynan occupies this span of ranting by clambering over Deekin's wings, while Deekin quietly takes notes, perhaps looking to expand his own magical repertoire.