Synopsis:
A strange parasite attaches itself to the heart of an FBI agent, who is a close personal friend of Broyles. Agent Dunham rushes to Germany to meet with an imprisoned man who reveals details of a larger threat and holds the secret of saving the dying agent. Meanwhile, Peter and Walter help Olivia by tapping into a dead man's brainwaves to get more information on the parasite. When the FBI agent is saved, it is revealed that he fits into a larger part of the conspiracy and the Pattern and may be working against the agency, unbeknownst to Broyles.