Construction workers discover a dead body as they fill an area with cement. The team questions the victim's ex-boyfriend. Captain Gates instructs the team to track down the murder weapon and bring it in. After further investigation, they find out that the victim's name is Jane. She works as a tutor and she had cancelled all her appointments the day of her death. She spent several hours going to different ATMs pulling out money and she was found with a cross in her hand.
The team goes on a search for the shooter. Beck and Ryan go to a bar hoping to find him under a new alias. It turns out to be an undercover narcotics cop enlisted Jane's help to bring down the Li family (Jane tutors their son). Castle tries to make a connection between the killer and the Li's. The Li's tell Beckett that they knew Jane was spying on them. Castle dives into their personal records and discover their eldest son Phillip is in prison. Castle investigation leads him Jane's boyfriend, Phillip's brother Ben. Seamus Denver tries to get Jane's ex to testify against Phillip.
Ryan talks Ben into helping them out and they set him up with a wire. He goes to speak with Phillip, who instantly knows something is up. Phillip pulls Ryan's gun out on Ben then the police come in. Ben accuses Ryan of ruining everything and gets shot by an officer. Phillip doesn't confess to anything but his possession of Ryan's gun is enough evidence to put him away. Phillip claims to have information about Jane's ex. Beckett has to decide whether to take Phillip's bait or put him behind bars.