On Quantico Season 1 Episode 21, the trainees have one week left til graduation. They are tasked with studying a terrorist attack and trying to find the suspect. They are given access to real life FBI evidence.
Alex and Shelby swap evidence access cards, so they can study attacks that they are close to. Alex wants to investigate Omaha, the tragedy that had a lasting impact on her father. She learns that her dad might have encouraged the militia to act, making him partially responsible for the attack.
Shelby's on a mission to bring her parents to justice. She gets a chance when her mom reaches out. Shelby steals evidence using Alex's key card, and she wants to forge an immunity agreement to get her parents onto American soil.
Nimah and Raina are given 24 hours to say goodbye to their lives. They have been given an undercover assignment. Raina isn't sure that this is the right path for her. She meets with Simon, and he suggests that she said yes to Quantico because Nimah did.
In the present, Alex is driving around with a bomb while talking to Drew. Except, it isn't Drew. The real Drew wakes up zip tied to Simon, hearing his voice coming through a computer. Drew and Simon manage to break free, and Drew tells Simon to get out to get to Alex.
Drew manages to talk to Alex to tell her that she wasn't talking to him. Then, the FBI bursts in and a bomb goes off, killing Drew.
Simon gets to Alex and tries to get her to open the door. He tells her the bomb won't go off. Alex is afraid to because she doesn't want to hurt innocent people. It was all theater in the end.
However, the bomb is stolen, and it looks like Miranda is behind it. When she goes home, she is met by the real terrorist - Liam.
He shoots her. When she asks why he's doing this, Liam says it is too make things right.