The terrorists responsible for the bombing of Grand Central Station finally reveal themselves, but instead of answers, more questions remain. While back at Quantico, the recruits receive a well-deserved few days off for the holidays, but not everyone is oh so merry when secrets are revealed and lines and blurred.

This week the NATS learn how to source information from confidential informants, but when they test their skills in the real world, they soon realize being an agent is not as easy as it seems. Meanwhile, in the future, Alex and a fellow agent find themselves in a life or death situation when they are forced to provide classified information that could result in deadly consequences.

A terror cell tries to infiltrate Quantico, forcing Miranda and Liam to pay a deadly price. While in the future, Alex continues to get instructions from the terrorist – only this time, it’s Claire Haas’ life that hangs in the balance.

At Quantico, the NATS’ current assignment is to learn about human trafficking when Liam and Miranda challenge them to cross the U.S. / Canadian border without passports. Meanwhile, in the future, Simon continues to help Alex try to find the terrorist, but doing so puts his own life in great risk.

It’s career day at Quantico as the NATS meet representatives from various FBI branches to help them decide their future paths. In the future, Alex continues to search for the terrorist, and in the process, discovers some familiar faces – including one who knows the terrorist’s endgame.