When Ted goes on a date without researching the girl on the Internet, the gang interferes, showing Kevin that they are too into each other’s business. Meanwhile, Lily and Marshall come to terms with finding out the sex of their baby.
Alicia takes a pro bono case in which a witness quickly becomes the prime suspect. Will and Diane plot the firm’s direction and their futures.
Brody prepares to enter the spotlight; Carrie closes in on an al-Qaeda plot.
Olivia uncovers a dangerous force that may be connected to past experiments with Cortexiphan. The investigation forces Walter to leave the lab for the first time in years and travel to Massive Dynamic to examine old case files. Walter struggles with his emotional state as he confronts the demons of his past.
While Lisbon looks into the death of a photographer at a political rally, Jane has his sights set on proving a man carrying a gun at the same rally is a psychopath with murder on his mind.
New roommates Troy and Abed host an apartment-warming party that takes a strange turn.
Gloria tries to help Jay and Manny with their problems but both are unreceptive. Claire considers running against Councilman Duane Bailey. Cam and Mitch are the victims of a hit-and-run accident.
Frankie learns that Axl’s PSAT’s are fast approaching and he hasn’t been preparing for them. Sue sets her sights high and decides to try out for cheerleading, while Mike decides that Brick needs to toughen up when he gets bullied at school.
While investigating the mysterious shooting death of a young woman, Castle and Beckett face a cop’s worst nightmare when they discover that the gun used in the killing is Det. Ryan’s old service weapon – the one that was stolen by the serial killer, 3XK. Now with the clock ticking, the team must work to solve the murder, track down 3XK and retrieve Ryan’s gun before the killer strikes again.
When Elisabeth, Jim, Malcolm and Taylor investigate radio silence at a nearby scientific outpost, they discover an outbreak of a mysterious virus causing memory loss, paranoia and eventually death. The group must work together to find a cure before they lose their sanity and all of Terra Nova is infected.