Just as Castle (Nathan Fillion) begins to think it’s time to sever his relationship with Detective Beckett (Stana Katic) the pair find themselves investigating a murder that, at least on the surface, looks like it was committed by a zombie. The initial suspect (Brandon Keener), the victim’s co-worker, was also attacked and is deathly afraid of what he’s sure was a zombie, refuses to leave the police station even after he’s cleared as a suspect in the murder.
Ryan (Seamus Dever) and Esposito (Jon Huertas) investigate the woman (Tiffany Dupont) the victim was seeing before his death, who it turns out is engaged to be married to another man (Ryan Doom) who just recently learned about her affair. A little leg work by Castle and Beckett also leads them to an abandoned factory where they find themselves, much to Castle’s amazement and horror, by a mob of zombies.
What they’ve actually stumbled upon is an underground group who enjoy dressing up as zombies and “normals” and acting out zombie attacks. This leads them to their killer, but he has no memory of the last 24hrs. and despite all the physical evidence that ties him to the crime Castle believes his innocence. Perlmutter (Arye Gross) confirms his suspicious by informing them their suspect was slipped with a drug that may have made him compliant enough to commit the murder without realizing it.
The episode also includes a couple of strong B-stories including Alexis’ (Molly C. Quinn) making her choice of college and lamenting the loss of her time with her father and Castle and Beckett coming to an understanding about their feelings without either admitting them in so many words. Next week’s season finale should be quite interesting.