I apologize if this question has been asked/answered ad nauseam, but I haven't been able to find an answer anywhere, and it's driving me crazy. I'm almost at the end of the game, and have been successfully returning to previous sequences to get 100% synchronization...but I cannot for the life of me figure out how to access the mercenary faction HQ mission that I skipped. Everything I've read says that it's accessible after Sequence 3, but if I return to 'The Prisoner', it's nowhere to be found. I've been searching through other random memories...I completed the thief mission during Sequence 3, and have tried returning to that memory in hopes that the mercenary one would show up at the same time, before I accepted the thief one... Am I completely missing something? Or is there only one chance to complete the mission?