Game Change
S6 episode 18 Aired on December 20, 2012

With Sam's health rapidly declining, the team rushes him to the home of a shady, but discrete doctor.

Sam is stabilized, but the team isn't given long to rest when they're attacked in the middle of the night by a team of cartel assassins. It turns out that Olivia Riley sent the cartel to kill Michael, promising them classified government intelligence in return. Riley's gone from using any means necessary to capture Michael, to selling out her country to have him killed. The only thing left to do now is bring the fight directly to her.

The team follows Riley to her next rendezvous with the cartel and calls Bly to meet them. Michael knows that if Bly sees Riley meeting with the cartel boss, he'll be able to expose her corruption and take her down.

But before Bly can report what he's seen to his superiors, a cartel guard kills him. Now Michael has no choice but to risk everything in a final showdown between him and Olivia Riley.