Having learned that she has been targeted for murder, Fiona attempts to learn her would-be assassin's name. She befriends Ayn, who supplies black market goods to the prisoners. Ayn wants Fiona to arrange for the guards to be locked out of the cell block in order to knock her new competitor out of commission. Fiona does so after creating a makeshift explosive device. Meanwhile, Pearce gets Michael's team to help her take down the man who killed her fiancé years ago. The man, CIA asset Ahmed Damour (Faran Tahir), has a hard drive full of valuable information that protects him. Michael, Jesse and Pearce accompany Ahmed on his vacation cruise, dose him with a drug that replicates the symptoms of meningitis, and quarantine him. Sam, Maddie and Nate go to Ahmed's home impersonating a medical team, to convince Ahmed's son Sharif that he is in danger of infection. They eventually recover the hard drive, rendering Ahmed expendable. Michael visits Fiona in prison, where he learns the name of a guard who is part of a plot to kill her.