Tessa, an insurance broker for commercial real estate, is found strung up dead on the ceiling by her roommate. The creepiest thing? She has a ritualistic symbol carved into her forehead. Other evidence: The murderer hung her body after he killed her, which he did by strangulation with a rope or cord. She'd been drugged (they found evidence of chloroform), and the team assumes she knew the killer because there are no signs of forced entry or struggle. There are also no signs of sexual assault or activity. According to Castle, this murder has "all the hallmarks of a serial killer." They identify the symbol on Tessa's forehead as some sort of ancient alchemy sign. The big shocker? They find Castle's fingerprints on the doorjamb, alledgedly from before Castle and Beckett arrived on the scene, meaning Castle might somehow be involved in this big mess.
First suspect: When questioned about his whereabouts on Friday, the night of Tessa's murder, Tessa's married boss Kurtzman asks for his lawyer. The team can't find anything to tie him to the murder and later find out he's a prostitute, not a murderer.
Evidence: Ryan finds a piece of custom Erica Courtney jewelry in Castle's sofa, so he contacts the shop, which has a record of the sale but bogus buyer information and an untraceable cashier's check (of course!). The team retrieves the surveillance tapes from the store and — shocker — see Castle on tape at the time of the purchase. Beckett is in complete disbelief that Castle could be a killer — and so are we! Castle would never be this sloppy!
Sidebar: Ryan tells Esposito about Beckett and Castle dating. "Normally I would be happy for them," Esposito says. They agree they need to prove Castle is not involved in this murder. Go, team!
Beckett goes to Castle's loft with a warrant, but demands an explanation. Ryan and Esposito find a bloody shirt, hooks, and wire in a bag in his apartment, and things really aren't looking good for Castle. Dun-dun-DUN! Esposito arrests Castle for Tessa's murder, but Beckett still doesn't believe Castle did it, though Castle has no alibi for the night of the murder. At this point, it seems obvious to us that it's totally not Castle because there is too much overwhelming evidence and what would his motive be anyway? That he's just insane?
Say WHAT? Castle Cheated on Beckett?!
Hello, heartbreak! Esposito discovers dozens of emails between Castle and Tessa that indicate the pair had been having an affair about eight weeks prior, which would have been just a couple weeks after Beckett started seeing Castle. And it just gets weirder: According to the emails, when Castle tried to leave Tessa, she threatened to tell Beckett about their affair, which gives him a motive for murder. Beckett is totally brokenhearted, but still doesn't believe any of it is true.
3XK (aka Jerry Tyson), dressed as a cop, confronts Castle in an isolated cell and tells him that instead of killing Castle, he's out for serious revenge. You see, Castle destroyed the mass murderer's would-be genius vanishing act, which 3XK devised so he could later come back and kill again. He creepily tells Castle, "People think it's killing that I like, but murder is just an act. It's all about the anticipation, the planning." 3XK also reveals he's watched Beckett and Castle doin' the dirty — um, ewww!
Castle and Beckett Reunite
Castle tells his story to Beckett, and — being the awesome girlfriend she is — she totally supports him, despite the lack of physical evidence of Tyson's appearance. Castle: "You believed me?" Beckett: "I never stopped." Awww. Cue super-adorable moment as the pair touches hands through the bars. Unfortunately, it isn't a conjugal visit...
Beckett Is on a Tear to Prove 3XK Is Involved and That Castle Is Innocent
Beckett swears, "Castle, this isn't over. I promise you I will get you out." Defeated, Castle responds, "That's OK. Whatever happens, it's OK."
Castle is being transferred to central holding and Beckett is racing to dig up evidence that 3XK is involved before Tyson has a chance to make good on his threat to have his people in central holding murder Castle.
Castle Stages His Transfer to Central Holding, Saves His Own Life
Beckett discovers Castle in the library, where Beckett first cuffed him. At this point, the DA has branded him a fugitive (and every cop is on his tail), so how the hell is he going to get out of this mess?
Unravelling Tessa's Murder
So how did Tyson get Castle on the surveillance video? Turns out the killer placed an ad for a look-alike in a casting magazine, which Castle traces back to the agency. The agency points him in the direction of the look-alike, who then ID's Tyson. Bam! In your face, 3XK! (Fun behind-the-scenes intel from Luke Reichle's Twitter: "Paul the waiter is Castle's regular stunt double. Even I do a double take sometimes.") Castle and Beckett then look up the look-alike's paycheck, which was closed down but was named cheekily after French serial killer Joseph Vacher. They find another check drawn on the fake account that was given to Kurtzman Insurance, Tessa's employer. They then check Tessa's appointment book and find a site visit with J.V. (Joseph Vacher) in northern Manhattan. Castle and Beckett then realize Tyson had been posing as a building owner, looking for a hideout or base of operations. They leave for the site and find enough evidence (photos, etc.) to get Castle's murder charges dropped. So, no, Castle is NOT a murderer! But this all seems a little too easily wrapped up...
3XK Has One More Dirty Trick Up His Sleeve
Like we said, it was all a little too easy! Just as we think things are all fine and dandy and Castle and Beckett are on their way home, Tyson ambushes them on the bridge by ramming into the back of their car. As Beckett springs to and shoots at Tysen, he fakes being hit (all Terminator-style) and then lunges at Beckett, intending to have Castle watch as he kills her. Clever Castle approaches him from behind and seemingly hits him multiple times until he flies off the bridge. Could this be the end of 3XK? Well, they haven't found the body. Castle is convinced the nightmare is not over, but is part of 3XK's grand plan to reivist his vanishing act so that he can kill again? Castle questions, "How does a wanted man stop being wanted? It has to be public and it has to be final."