Castle celebrates its 100th episode with a homage to Rear Window as Castle (Nathan Fillion) believes he witnesses a murder while cooped up in his apartment two days before his birthday with a broken leg. While Castle goes stir crazy, Beckett (Stana Katic), Esposito (Jon Huertas), and Ryan (Seamus Dever) investigate a woman beaten to death with a baseball in a back alley whose body was left in a dumpster.
While Beckett talks with the victim’s husband (John Griffin), Ryan and Esposito head to the IRS where the woman worked as an investigator to try and find the identity of an irate auditee (William deVry) before being called by the mystery writer to investigate a murder across the street from his apartment. Without any signs of a struggle, blood, or a body, and the only witness being a very bored and imaginative writer hopped up on pain killers, Beckett and their team have no choice but to dismiss the incident as something Castle hallucinated. Castle, however, is far from convinced as he continues obsessing on what really happened across the way.
Alexis (Molly C. Quinn) stops by to check on her father and talk through the events to find a logical explanation for what Castle witnessed but only finds herself drawn into his obsession. After witnessing the man shredding the credit cards of a purse in his apartment and discarding large bags of trash from the bedroom, Castle decides to break into the apartment and find the proof necessary to convince Beckett of what he’s seen. Despite being furious at what the two of them have done, Beckett finds herself drawn into the case as well after she questions the man the supposed murder victim was sleeping with as well as the missing girl’s parents, neither of whom have heard from her in two days.
After the two are caught breaking and entering the man’s storage unit (which doesn’t contain a dead body) Capt. Gates (Penny Johnson) reads both of them the riot act before throwing them out of her office. After Castle solves the crime by deducing where the killer stashed the dead body Beckett agrees to humor him one last time before ruining his birthday plans, but when she’s attacked in the apartment Castle fears the worst… at least until the episode’s big twist (which I certainly won’t spoil here – even if it is insanely over-elaborate).
Meanwhile Esposito and Ryan discover their victim was taking payoffs from a crime boss (Sal Viscuso) and making plans to disappear into a new life and identity in the days leading up to her death and learn her relationship with her husband may not have been as happy as the picture he painted for them. The big payoff of Castle’s case gives Beckett the final clue to solve her own murder and the cover-up involving the victim’s husband and the security guard (Raquel Alessi) who worked in the building where the woman was killed.
As a big fan of Rear Window, I love all the touches and nods “The Lives of Others” contains (including Beckett’s version of Grace Kelly‘s style of hair and dress and several distinct camera shots). The payoff to the episode is pretty ridiculous, but it certainly fits within the bounds of what the show has given its fans over the years, provides numerous humorous and tense moments, and offers a unique mystery for the show’s 100th episode that (as Beckett notes) will be hard to top.