The interrogation scene in “Mind Games” stands out for me as one of the more memorable scenes in STO. It gives you a glimpse of the working relationship between Hakeev and Sela, and basically how each keeps the other in check. It was fun to see them try and play good cop/bad cop with you; with Sela imploring you to just talk so she doesn’t have to give you over to Hakeev (who would like nothing more than to use his experimental brainwashing methods on you, the separatist on whom he has sworn bloody vengeance).
Sela essentially gives you over to Hakeev to ensure his loyalty, because even though she doesn’t like him, she knows he commands the loyalty of the Tal Shiar (and she can’t risk them turning on her). It seems like your character knows she would do that to keep in him check whether you talked or not, though.
Hakeev also chafes at Sela’s command, but he generally keeps the Tal Shiar in line for her as long as it serves him. Just as Sela doesn’t dare alienate the Tal Shiar, Hakeev doesn’t think that he can stand to alienate the Imperium. And, just as she had feared, pretty much as soon as Sela turns on Hakeev and abandons him to die, the Tal Shiar turns on the Imperium and makes its power grab.