"Answer" is all about the men in Alex's life. When you think about it, it's kind of fascinating that Quantico has managed to keep her relationships with each of them so distinct. Although some are absolutely crucial, others she barely interacts with at all. (Namely Caleb, who doesn't really share scenes with people not named Shelby.)
So, let's break down this episode by talking about each of these characters, and where things stand between them and Alex.
The present-day plot of "Answer" mostly takes place in the wilderness of Holland, Vermont, where Simon Asher has been hiding since the disaster that destroyed the FBI command center in New York. He hasn't really made an appearance since the show returned from hiatus, but following her breakdown in Ryan's apartment, Simon is the only person Alex feels like she can trust.
Unfortunately, Simon isn't in a good place — he contemplates suicide daily, sitting down in his little cabin and making a habit of putting the barrel of a revolver in his mouth. Simon has always been Quantico's most tortured character, in a way that's bleaker and more tragic than just about anything else the show has thrown our way. Simon's current state seems like a bit much, but the guy was barely holding on to begin with — and thanks to the FBI's complete failure to find the right bomb in the mid-season finale, he's inadvertently responsible for all those deaths.
Alex has gravitated to a similar darkness ever since she's been on the run. She knows that Simon has long held terrible secrets, and trusts him even though it's impossible to know whose side he's really on. While their friendship has been kind of one-sided — its mostly been Simon helping Alex whenever she shows up at his door — today she gets to pay him back, talking him down from the brink and convincing him that what he wants isn't a way out, but a way back.
In the final moments of the episode, we find out her intervention worked: He shows up at her door with a way to trace the mastermind's call.
Quantico's newest hunky dude is the crux of the episode's flashback story, which involves interviewing actors who play real-life criminals that got away because they were never convicted. It's the NATs job to figure out where real-life agents went wrong, so they need to ask the questions that should have been asked, in order to avoid making the same mistakes.
The exercise mostly is a backdrop for Alex and Drew to talk about the murder of his beloved Alicia in Chicago, a crime Alex suspects might be related to the operation gone wrong that nearly cost Liam his job and sent Ryan back to training.
Alex finally asks Liam for the full story, and it's pretty simple: O'Connor had set up a sting for a renegade militia outfit, selling them weaponry and baiting them for a raid, only they got tipped off and were already gone when the FBI tried to rush in to salvage the op. No one died, but as an enraged Drew tells Liam in the middle of class, those weapons were later used on a train attack in Chicago that killed two people, including Alicia.
Thanks to Alex, Drew gets his closure, but he loses his future with the Bureau. Liam sends him home for his outburst, telling him there's no room for agents who lose their cool.
For almost the entire season, it's been hinted that something transpired between Alex and her former teacher. "Answer" finally says it in plain English, even though we didn't really need anyone to tell us — Liam and Alex slept together after the Haas New Year's bash. Though they agreed to not talk about it, it surfaces following Drew's revelation about the failed sting.
It's always been hard to suss out why Quantico made Liam and Alex a thing — they don't have the most obvious chemistry, and both seem like they're smarter than that — but when Alex confronts him about Drew, Liam comes out swinging with some dickhead defense. He says that Alex wants some sort of hard case to make him a bad guy, to make it easier for her to hate him and the fact that she slept with him. He even accuses her of having daddy issues, saying that "we're always talking about" her father and suggesting that her self-destructive acts are rooted in the fact that she killed someone people believed to be a hero.
Shaw, however, notices the argument between them. Now she's finally certain, she tells O'Connor that she knows he slept with Alex, and she expects his resignation in the morning.
It always comes back to Ryan, though. The only guy here to get something of an arc in both the past and future timelines, Alex spends the majority of "Answer" trying to get up the nerve to do one thing: Call him.
In the Quantico timeline, it's because she has his dog tags and can't bring herself to ask where he is. If she sends them back, it would mean finally admitting they're over. In the future, a call would mean finally admitting she's not okay. She'd be asking for help of her own accord, and not under the duress of a terrorist pulling the strings.
She finally decides to do it after Ryan drives out to Vermont with Nimah to find her. On the ride back with Nimah (while Ryan is in a separate car), the two ladies talk about how they've all changed since the attack on Grand Central — and Nimah points out that Ryan is the one person who hasn't. And so she returns home, and calls him.
A few other things happen in this episode, inching Quantico's various subplots forward little by little. Will Olsen discovers Caleb's "Mark Raymond" alias, and when he asks him about it, Caleb threatens him. This, of course, only fuels Will's curiosity, so he follows Caleb as he meets with Samar, who's elaborate con of Shelby seems to be even more elaborate than we thought.
Also, Nimah impersonates her sister and finds out she's been infiltrating the terrorist cell Charlie was roped into for Miranda, but Nimah doesn't fully believe her, or at least doesn't feel Raina has been honest with Miranda, whatever that means. Regardless, she's off to fix what she sees as Raina's mess, and I'm pretty sure it's not going to end well.