The Amentans relax considerably. Someone calls something over to the grey in the shower. "Do you have a particular sort of person who handles the waste systems and body disposal?"

"Engineers deal with the waste systems and hazmat teams deal with dead bodies and waste system failures--although the latter are extremely rare." 

"Do they have a way of thoroughly cleaning themselves when they're done with work for the day?"

"...They shouldn't need to unless something goes wrong with their hazmat suits, but yes, of course. Anyone exposed to foul water is thoroughly cleaned and checked thoroughly for infection." 

"That's good to hear. We used to have a caste dedicated to dealing with unclean things but with recent technology it was possible to transition them into other castes and have enough barriers between workers and their work that purples can do the same things."

"You had a caste for that? That sounds extremely unfortunate for them. Before doing foul water cleanup could be done safely with hazmat suits it was a job for condemned criminals." 

"That seems like a reasonable setup! It's not the one our ancestors settled on and it was difficult to break out of the equilibrium once it was in place. Now all of the reds have chosen new castes and integrated into them."

"I'm very glad to hear that. It seems like a transition that would benefit everyone." 

"We're glad we've finally managed it."

"It sounds like it must have been difficult. We commend you."

"Thank you. Is there anything else we should bring back from Amenta the next time one of our ships make a trip that hasn't come up yet? People back home are eager for news and one of our ships in orbit is getting ready to depart to tell them what's going on."

"We would love to examine whatever public pharmaceutical science you could provide."

"We can get you data on that!"

"Thank you!"

"Anything else?"

"I'm sure if I gave my assistants and the scientists a few days they could come up with a whole laundry list but I'm certainly not thinking of anything at the moment."

"Well, in a few days we'll be able to send another! We're having ships going back and forth every day."

"Is that a lot? I confess none of us have been able to grasp the full implications of this technology."

"It's a lot, but we want to be able to get any personnel who turn out to need to be here in place quickly. We're really invested in doing first contact right. We have subspace communications that let us talk to Amenta faster than the ships go, so a ship already on its way to Amenta can pick up things and people we didn't know to ask for before it left."

"That seems incredibly convenient--" they turn their head to look at some of the scientists they brought with, who look incredibly excited. "--and apparently technologically exciting, too."

"It is! It was relatively easy to figure out after we had the breakthrough that led to warp drive, but none of us are experts on how it works. Should we fetch some?"

"That would be incredible!"

"We'll let them know!"

A couple of days later a subspace communication expert arrives, and so does a sculpture for the merpeople to put wherever they think it would look nice (it's made of concrete with glass embedded in it to make it glitter in a lot of colors, and was originally intended to be sunken artwork, seized as a diplomatic gift at the last minute; it depicts an Amentan eel with some liberties taken on its color scheme).

The mermaids ooh and aah over the sculpture, which is then displayed at the edge of the shelf, so that it can be seen both above and below the water. Mermaid construction teams are busy creating a permanent diplomatic installation just off-shore with a permanent fiber optic data connection. In the meantime, the Amentans can access mermaid internet through the temporary ELF transmitter. 

The Amentans are all over mermaid internet! Their machine translation is getting better over time as they flag things for the computer to chew on harder and bring up persistent linguistic confusions with the merpeople. What's on the mermaid internet?