Beckett arrives at a 86th Street crime scene to find Ryan and Esposito in the building’s basement laundry room, where we’re shocked to see a nanny named Sara Manning’s body inside a dryer.
Next we see Castle and Beckett interview Sara’s employers, Claudia and Howard Peterson. After Sara failed to pick up their son Justin from school, Claudia tried to call her, but got no answer. Beckett digs through Sara’s purse, but can’t find Sara’s cell phone. Hmmm.
[break] They return to the precinct to find Montgomery, Esposito and Ryan studying the video, in which we see Sara entering with a laundry basket and exiting at the basement. A few minutes later, she’s back upstairs. Forty minutes after, she enters the basement for a second time and we never see her again. The cops conclude that the killer must have used the stairwell or already been in the basement when Sara arrived.
At the morgue, we learn from Lanie Parrish that Sara was killed by a blow to the back of the head, and then struck her temple on the edge of the folding table. They also learn that Sara had sex shortly before her murder and the man wore a condom.
At the precinct, both we and the cops are skeptical of the sexual predator theory—rapists don’t ordinarily wear condoms. There’s also still no word on the missing cell phone. Esposito, however, has gotten the service provider to “ping” the phone. It’s near or inside the apartment building.
[break] Looking at the phone records, Beckett notices dozens of calls to Sara from the same number in the past two months. She also sees that Sara stopped returning the calls a week before they stopped. We find out the calls were from Brent Johnson, her ex-boyfriend. Castle and Beckett interrogate Brent, who admits that Sara and he split but claims it was mutual. He also has an alibi for her murder—he was at work. In fact, Brent found out about Sara’s death through a mutual friend from college, Chloe Richardson, who nannies in the building for another family.
They spot Chloe, who reveals to us that Sara had started staying late for the Petersons—but only on the nights Howard Peterson was home.
We see Beckett confront Howard. At first he denies it, but after some prodding from Castle, Howard admits to having an affair—but not with Sara.
Now Ryan jumps in: “Guess who wasn’t where they said they were the day Sara Manning was killed?” The answer, we find, is Claudia Peterson, whom Castle and Beckett question. Claudia confesses she was actually at her lawyer’s office, getting ready to serve her cheating husband with divorce papers.
[break] At home, Castle studies the elevator camera videos. We watch Sara Manning appear on two monitors—riding to the basement with the laundry basket and, the second time, riding down to put the clothes in the dryer. There’s a five second difference in time.
Castle and Beckett then ride the elevator with Castle timing their ride from the basement. When the doors open, they’re on the 15th floor, where we recall Sara came from when she went down to the basement to put clothes in the dryer. But the Petersons live on 12.
Castle starts knocking on doors. We watch Beckett and Castle question a woman named Diana, her husband Ian saunters in from the bedroom. Castle then asks to use their bathroom, where he finds a box of condoms. He dials a number and a phone begins to ring somewhere in the apartment. Uh-oh! Diana finds Sara’s phone in the bedroom.
[break] At the precinct, we hear Ian Harris confess to having sex with Sara, but swear he never hurt her. He tells them that Sara left his apartment about ten minutes before Chloe got back from the park.
They review the elevator footage and it looks to us like Ian Harris was telling the truth.Beckett notices Becca isn’t with Chloe in the elevator tape. As Castle notes, coincidences don’t just happen—not when a murder is involved. Chloe would have known from Sara’s schedule that she’d be in the basement.
Beckett and Castle visit Chloe’s apartment. Her roommate Bethany claims Chloe had to go baby sit. We then see a photo in Chloe’s room—Ian and Becca Harris with Chloe—Diana Harris having been cropped out of the photo.
[break] Castle and Beckett arrive at the apartment building and find Esposito and Ryan waiting. Upstairs, we find Ian Harris knocked out on his living room floor, and Diana and Becca locked in the bedroom, but safe.
Now it’s all revealed to us—Beckett finds Chloe sitting in front of a dryer, holding a butcher knife. Chloe tells them she and Ian had been having an affair, and that she’s pregnant with his baby. When she found out that Sara was sleeping with Ian, Chloe killed her in a jealous rage. Explaining that she can empathize with Chloe’s heartbreak, we watch as Beckett is able to convince Chloe to put the knife away.
At home, Castle writes on his laptop. Alexis stops by to ask if they caught the culprit, and if Castle was right about who the killer was. In fact, Castle tells her, he wasn’t. Alexis reminds him that it’s fun to be surprised sometimes. As she exits, we get a bit choked up as she thanks Castle for having been her nanny.