If there is, I haven't heard of it. [She says with a shrug.] It does seem odd, I wouldn't say any of the planets we've visited as long as I've been here have been technologically incapable of communication. Most of them have had Ingresses, even. Perhaps there is communication, however given most of our stays don't amount to more than a month and a half, it goes unnoticed by us.

[...of course if there was communication, at least from Caducus Primary, Elizabeth would be surprised if anybody let them on their planet.]

[She stops in front of the shelf, towards the front of the library. The shelves are healthy, yes, but there's clearly room for the collection to grow.] Here we are. So, several of these are from Captain Thán's collection, things he collected before I arrived. But the first planet I saw--

[She pulls a book off the shelf carefully, and no doubt Duv can see why immediately. The cover is made of glass.]

Caducus Primary. Almost all of their infrastructure was made of glass.