Castle witnesses one woman murder another at a party and then flee. Five months later he’s called as a witness for the prosecution. When Caleb Brown takes over the defendant’s case at the last moment, he tears Castle apart on the stand bringing up his previous eight weeks of memory loss and the fact that he was once accused of murder even though he was innocent. 

Castle, Espo, Ryan, and Beckett meet at the 12th to try and find more evidence against Nina to save the case. They find video of Nina and Sadie kissing. It looks as though Nina killing Sadie was a crime of passion until Castle and Ryan realize that the portable basketball hoop was moved before the party to allow the killer to climb down it and flee. That means the murder was premeditated. 

When Castle tells Marcus, the prosecutor, that he has doubts, Marcus gets angry, saying he’s done enough damage to the case and to stay out of it but Castle and Beckett continue to investigate. Rick tells Martha and Alexis he’s come up with a plan and it involves him getting arrested. 

Rick asks the judge for a do over and pushes her to hold him in contempt of court. She lets him go because of his relationship with the mayor. Then Rick insults her college and he’s thrown in jail for contempt. He gets in a cell near Nina and she tells him that she was trying to save Sadie but she knew how it looked so she ran. Rick promises to find the truth but the judge calls the trial back into session in a half hour. 

Kate makes sure that Caleb calls Castle to the stand where he says he no longer believes that Nina is innocent. when Castle goes through the events again, he remembers a man stepping out of the bathroom with mud on his shoes just after the murder. That man was the victim’s husband. He thought that Sadie was having an affair with their friend’s husband and moved the basketball hoop so he could climb to the second floor and spy on them. He was furious that Sadie was having an affair with Nina and he killed her.

Kate realizes that Caleb Brown is a public defender that wants to do good even though he’s the monster behind LokSat. She tells Vikram that she can use that against him to take him down. Then she goes home to share an evening with her husband.