On Quantico Season 1 Episode 18, the NATS are tasked with passing the medical screening and getting approved for security clearance. The SF86, the application for security clearance, is extremely detailed and personal.
Some NATs were flagged for review, and the ones who passed the security clearance test are tasked with investigating one of the flagged NATS.
OPM comes to a conclusion on all but 4 of the flagged trainees, including Raina and Drew. They are both cleared, but Iris is not. To retaliate, Iris calls up Sistemics saying that a new potential member is FBI. This puts Will's life in danger, and Caleb has to show up to Sistemics and prove that he isn't friends with Will by beating him up.
Miranda was removed from her position at Quantico and demoted to Special Agent. She has sex with Liam and records him saying that it was only a one time thing with Alex. When that proof doesn't land her job back or kick Liam out of the running to take her job, Miranda goes to Alex to warn her about how the FBI is a man's world.
The Voice's car that Shelby was driving was rented by Mark Raymond. Alex tries to get in contact, and when that fails, she digs into Mark Raymond. When she learns that he is Caleb, Alex recruits Raina to help her out.
Senator Haas takes Alex to Caleb. While the official story is that Caleb is deep undercover, the truth is that Caleb is a drug addict. The Senator is keeping him under wraps because she can't admit him during the campaign. But things are never what they seem.
As Alex stands outside calling Raina, Caleb shows up. He's breaking out to help Alex, but when she's out of earshot, Caleb makes a phone call saying that "she fell for it."