A cheap motel in Boston. A young man, whose name we later learn is CHRISTOPHER, has just had a one-night stand with a stripper, LORAINE. Just as he steps into the bathroom and opens a medical bag filled with creepy metal tools, he hears Loraine scream. She's suddenly in terrible pain, seizing her stomach and crawling out the door. Christopher abandons his mysterious preparations and helps Loraine into the car.
En route to the hospital, Loraine's stomach is growing and undulating. Christopher dumps her on the curb at the hospital and takes off. In the E.R., doctors ask how far she is into her term - but she has no idea she's even pregnant! As she goes into labor and the doctors prepare to deliver the baby, they hear a nauseating tearing sound. Loraine flatlines. The doctors quickly slice open Loraine's massive abdomen for a C-section, and upon seeing what's inside, their eyes widen with fear and a nurse screams in horror.
Downtown Boston. Special Agent Phillip Broyles meets with the members of a top-secret committee whose mission is to investigate The Pattern. Shortly thereafter, he calls Special Agent Olivia Dunham of the FBI, whom he recently recruited to head up a special team to cover Pattern cases, and tells her to assemble her team.
When Olivia arrives at Walter's and Peter's hotel to pick them up, Peter finds Walter huddled in the closet. Without the familiar sound of "Row Row Row Your Boat" sung by one of his fellow inmates at the mental asylum where he spent the last 17 years, Walter just can't fall asleep.
At the hospital, Broyles explains that our Jane Doe (Loraine) died shortly after arrival, and the baby she birthed grew into an old man and died of "natural causes"... all within a half hour. As Walter inspects the body of this bizarre man-baby, Olivia and Peter head to the hotel to investigate the crime scene.
Peter finds a strange orange gel in the bathroom. In the bedroom, Olivia recognizes the tell-tale signs of a serial-killer case she had worked with her former partner (and secret lover) John Scott. The killer would take a woman to a motel, paralyze her, then use surgical tools to go through the nasal cavity and remove a piece of the brain. If Olivia's right, this is the same guy -- and he's going to kill again.
Meanwhile, Christopher enters a club and picks up an attractive young woman, his next victim. He brings her back to a warehouse loft. While she looks at the view of a bridge through the window, Christopher prepares a syringe - which he suddenly jabs into her neck.
When Peter returns to the lab, Walter says that he has fantastic news: he remembers where he parked his car seventeen years ago! Together they head to a locked garage, where they find Walter's station wagon parked exactly where he left it - with Walter's files stashed inside for safe keeping. Peter reveals his mechanical skills by bringing the old car back to life.
His memory jogged by his old files, Walter finally recalls having worked with one Dr. CLAUSE PEROSE on experiments dealing with rapid growth thirty years ago. It turns out Clause is currently a professor at Boston College. Meanwhile, Christopher continues his gruesome work, finishing off the young woman at the warehouse.
At Boston College, Olivia and Peter question Claus Penrose. He remembers the work he did with Walter, and to this day feels it was morally wrong. As a result, he quit working for the U.S. government after only one year. Charlie calls to inform Olivia that they've found the latest victim, and she was right: this must be the same killer, because the victim's pituitary gland has been removed.
With the latest body back at the lab, Walter finally remembers the specifics of his project with Penrose. The U.S. Army had tasked them with finding a way to cultivate soldiers, who could mature to prime fighting age in a short period of time. But the project failed because they could never stop the aging process. Walter hypothesizes that someone must have made a breakthrough, and the killer is in fact the product of the experiment. The killer must extract the pituitary gland from his victims' brains in order to keep his own aging process in check. And he transmitted his own rapid-aging condition to the child he conceived with Loraine during their one-night stand.
Back at Christopher's loft, the killer meets with a confidante, and it's none other than Claus Penrose, who refers to Christopher as his son! Christopher is in increasing pain, and he needs the pituitary from another victim.
In the lab, Walter posits that they may be able to recover the last image the previous victim saw from her optic nerve. But to do so, they will need a sophisticated piece of equipment - equipment that only one company has the patent for: Massive Dynamic.
Olivia heads to Massive Dynamic to meet with Chief Operating Officer Nina Sharp. Nina, as helpful as ever, offers up the electronic pulse camera, which Olivia takes back to the lab. Walter and Peter assemble the machine and start the process of extracting images from the victim's eye.
Christopher enters another bar and finds his next victim, bringing her back to the loft. Meanwhile, Olivia's team manages to extract a single image from the last victim's optic nerve: a bridge, which they are able to identify as Sergeant Bridge in Stoughton, Mass. They match the angle and triangulate the location to a building in a warehouse district.
Olivia and Peter race to the warehouse loft, where they find the next victim strapped to a table - and Clause Penrose waiting for them. Olivia hears a rattle and moves to chase Christopher, leaving Peter to guard Penrose. Penrose adjusts the victim's IV drip and her vitals spike, giving him just enough time to run. Peter, forced to choose between going after Penrose or saving the victim, assembles a make-shift defibrillator (with Walter's help via cell phone) and shocks the victim's heart back to life! Elsewhere, Olivia corners Christopher. But he no longer looks at all like the man who murdered all those women. He's a gray-haired man now, aging decades right before Olivia's eyes. With his dying breath, he confesses that he was an experiment - that someone made him. And blinded by love, his father refused to let him die.
Later. Olivia returns the pulse camera to Nina - who surprises her by offering her a job heading up security at Massive Dynamic. Back at the FBI, Broyles reminds Olivia that everything associated with these cases is strictly confidential, and even though people such as Nina Sharp do have some clearance, she is not to discuss cases with anyone.
Peter and Walter's hotel. Walter again struggles with insomnia, keeping his son awake by reciting an endless sequence of numbers. In an attempt to lull his father to sleep, Peter offers an annoyed rendition of "Row Row Row Your Boat." As Walter closes his eyes, the scene shifts to an undisclosed location, where there are three young men in what appear to be incubators... growing.