Nickamedes is a Spartan and the head librarian at the Library of Antiquities. Nickamedes loves the books and the artifacts in the library more than anything else, and he doesn't seem to like Gwen at all. In fact, he often goes out of his way to make more work for her whenever Gwen is working after school in the library.
Nickamedes is Logan's uncle, although the uptight librarian is nothing like his easygoing nephew. It is said in Kiss of Frost that Nickamedes and Logan's father don't share a nice relationship.