The 100th episode of Castle has a very Rear Window-ish feel to it. Our favorite mystery man is stuck in wheelchair after breaking his kneecap while skiing. He uses a pair of binoculars Alexis got him as a joke to check out the residents in the apartment building across the way. He sees two writers hard at work. The male scribe looks suspiciously like series creator Andrew W. Marlowe. The other writer is his wife, Terri Edda Miller. The two of them co-wrote this particular episode.
As he continues to do the Peeping Rick thing, Castle catches sight of a young woman engaged in some afternoon delight with a young man with a black hat. The flirty lady shuffles her lover out the door when her main squeeze comes home unexpectedly. Too bad her fleeing paramour left his stylish chapeau behind. The apartment tenant knows this lonely lady is being unfaithful. He takes a knife and follows her into the bedroom. The blinds are closed as an attack take place. Holy MacGuffin! Castle believes he just witnessed a murder.
Speaking of murder, apartment building security guard Selena Rigas notices a figure walking down an outside alley on her surveillance monitor. No face can be seen thanks to the bright light shining above the neck. The figure attacks a woman with a bat. A second security guard rushes into the alley, but he’s too late. Clara DeWinter is dead in a dumpster. The killer’s car is seen on the video footage. Clara’s husband, Gavin, says his IRS agent wife had been threatened by a tax cheat she took down. Beckett’s investigation gets put on hold when Castle calls about the murder he saw through his binoculars.
Beckett, Esposito and Ryan check out the apartment across from Castle’s loft. There’s no sign of foul play. The man in the apartment says he had a fight with his girlfriend. They broke up before she left the apartment. A call to the woman confirms that she’s alive and well. Castle is thoroughly confused. He awakens in the middle of the night to spy on the apartment. Beckett believes he’s obsessing over an imaginary murder because he’s bored. Castle begs to differ. He later sees the guy washing away blood in the sink. He also notices that some rope and a tarp have been purchased. Castle is truly dismayed that Beckett still doesn’t believe him.
Castle continues to keep watch on the apartment across the street. He catches sight of the tenant dragging a rug across the room. There could be a body inside. Alexis joins her dad in his snooping venture since his murder suspect has washboard abs. She’s a little freaked when she sees the guy donning rubber gloves and a respirator mask. Castle enlists Alexis to be his lookout as he breaks into his suspect’s apartment. He finds what look to be blood spatter on the closet wall along with cleaning supplies. Castle hides under the bed when the apartment tenant returns. He manages to sneak out with a bag of remnants from the shredder.