Hrolf (not his real name) is a talented human spy from Altdorf. He has apparently been sent here by the dwarves to spy on Gina, although she has already ID'ed him, unbeknownst to him.
Kogo was found by Gina when she needed someone to help tail Hrolf. Rumor has it that he's being developed as an intelligence agent by Ageron. He certainly knows all the lingo of the spy trade, and definitely seems enthusiastic. It remains to be seen …