This week, we learn more about Echo/Caroline's past and how she came to be at the Dollhouse when a drug is released at her former school by a company associated with the Dollhouse. Nearly all of the Actives are sent to contain the threat and Echo is inexplicably drawn to join them. Hijinks ensue.
Through a series of flashbacks, we get more backstory on how Caroline came to be Echo. After graduating from university, Caroline became concerned with the animal testing the Rossum Corporation was doing in the lab building that is named after them on campus. She recruited her boyfriend to help her sneak into the Rossum building and videotape the experiments, hoping that exposure would shame the Rossum Corporation into stopping animal testing. When they enter the lab, though, they find out that Rossum is also testing on fetuses and human brains. Before they can find out more, a security guard finds them. While trying to escape, Caroline's boyfriend is shot. They manage to make it out of the building, but he dies on the campus lawn. Caroline is apparently caught, because a security guard alerts Ms Dewitt to a woman "matching the description". When Adelle arrives, though, Caroline has escaped. Eventually, though, she is captured for good.
We next see more of the scene between Ms Dewitt and Caroline that opened the series. Adelle makes references to them "dancing this dance" for years now. References are also made to crossing Rossum. Eventually, Adelle lays out her offer. If Caroline gives Adelle five years, she can have the rest of her life free, clear, and better than it was before.
In the present, in that very same Rossum building, two lab workers (grad students?) come upon their colleague, who is having some serious issues. He babbles at them about flies and gravity before running into a full length window and trying to head-butt his way through until he kills himself.
The Rossum Co-Chair and exposition fairy shows up at the Dollhouse to explain that the kid was tripping on some kind of mind-control drug that breaks down inhibitions and makes you act solely on impulse. There also seems to be a vial missing and the co-chair wants Topher to work out an antidote while an army of Actives tries to quarantine the school before the entire student body is drugged. Topher explains that Actives shouldn't be affected since they're blank slates under their imprints. Their only impulses would be the imprinted ones.
We also begin to find out that Rossum and the Dollhouses are all part of the same organization, which makes sense considering the mind-control aspect of things. The question is - do the Dollhouses exist to test Rossum's products? Does Rossum exist to provide the products that the Dollhouses use? Is it even bigger than either of them?
Regardless, Adelle cancels all engagements to provide the personnel needed to quarantine the school. All engagements other than Echo's, rather. There's more going on between those two: Why does Adelle consistently go out of her way to protect Echo?
Anyway, the Actives hit the ground running. Victor has been imprinted as an NSA agent, Sierra as a CDC doctor, and the handlers are posing as Rossum security and support personnel.
While on her engagement, Echo sees a news report about what's going on at the college and suddenly has an urge to go save "him". Though it's not clear at this point in the episode since the flashbacks are interspersed throughout, we know that the dead boyfriend is "him".
When she shows up at the school, she is intercepted by Victor who takes her half-memories as a sign that she's been drugged and sends her to the quarantine, where Sierra is waiting to give her a sedative. Instead, Echo meets up with one of the dead student's friends who also wants to get into the lab, supposedly to gather evidence that Rossum purposely released the drug into the student population. They run into Langton, who Ms Dewitt sent to get Echo away from the school, but he's been infected by the drug as well and starts tripping out.
Meanwhile, Topher has injected Melli (what is her Active name, anyway? Did I miss it?) with the drug to see how it works. While he's running tests, though, he and Adelle both beginning acting erratically. Topher realizes that they both now have the drug in their systems and it must be spread by touch. He calls the team at the college to warn them to get all of the handlers away, but - as evidenced by Langton - it's already too late.
About this time, Mellie wanders out and begins showing signs of her Mellie imprint, which makes Topher realize that the drug eventually effects Actives and manifests as "memory glitches", which was already happening to Echo. The good news is that the drug is devolving and will eventually pass out of everyone's system.
Of course, this means that the kid who killed himself was overdosed and would have never have taken that much voluntarily, which means he was actually murdered.
Back at the Rossum building, everyone is converging. Echo and the grad student have snuck into the building and are trying to dodge security guards and actives. They run into Dominic (Adelle's pit bull), who is also tripping. He continuously apologizes for trying to kill Echo, who has no idea what he's talking about (she's still in her engagement imprint) but accepts his apology anyway, though he doesn't believe that he's forgiven.
Victor and Sierra are also glitching. Victor is flashing back to either his real life or an engagement as a soldier who is trying to comfort a hostile Middle-Eastern woman. Sierra is flashing back to her rape by her former handler and trying to fight off what she sees as her handler but is actually Victor. It looked like Sierra shot Victor, but he's fine later, so I'm not sure.
Echo and the lab dude finally make it into the lab, where she begins remembering just what happened the last time she was there. The lab dude goes to a cabinet of samples and pulls out the other vial, which was hidden in another sample. When Echo realizes what is going on, he explains that he and his friend (the dead dude) were going to steal the sample and sell it to another drug company. When his friend chickened out, he drugged him in order to keep him out of the way long enough to escape. Unfortunately, he gave his friend too much and... deadness ensued.
He drugs Echo with a lower dose and makes a run for it, but Echo - in full flashback mode now - chases him through the building and tackles him on the front lawn, roughly where her boyfriend died. Langton conveniently shows up at that moment to take the lab dude into custody and Echo to her treatment.
Once all personnel is secure, Adelle meets with the lab assistant and offers him the same deal that she offered Caroline in the beginning. If he signs up for five years, his mother will receive a monthly stipend to cover her bills and, at the end, he will be in a position to take care of her for the rest of her life.
Also, The Dollhouse has apparently decided to recall Mellie for awhile. After fighting about his refusal to drop the Dollhouse case, even though he's been suspended, Mellie tells him that she's freaked out about the whole attempted murder thing and is going away for awhile.
Next week, it looks like all of the Actives will be awakened to their original personalities somehow. I bet Alpha's in on that.