While sifting through the senator’s threatening hate mail, Beckett comes across a note that’s a viable lead. She pockets the letter before Castle can see it. The handwriting matches that found in a notebook used by a suspect they’ve identified through the rifle’s serial number. Beckett talks about hiding the evidence to her therapist, Dr. Burke. She believes that if she finds this suspect then someone far worse is going to escape justice. There’s no right choice here. She holds a match over the letter. If she burns it, this particular lead goes up in flames.

Beckett doesn’t burn the letter. She’s about to tell the team about it until another lead sends them to Jersey where they find the home of a mechanic named Robert McManus. The guy has a schizophrenic history with recent episodes having been triggered by his son’s death. As the team checks out the suspect’s apartment, Beckett comes across McManus in the hall. She draws her gun, but the guy takes off. BANG! BANG! Beckett has McManus in her sights, but her two shots only hit a back wall. Did she miss on purpose?

Beckett comes clean to Castle about the letter. McManus believes Bracken killed his son, who was an intern for the senator’s reelection campaign. He was found hanged shortly before he was to meet with a reporter presumably about something he had on Bracken. Beckett could see the pain in the eyes of McManus. It’s the same pain she felt with her mother. Beckett wonders if she wanted the guy to get away with killing Bracken. Her guilt is compounded when Captain Gates tells her that McManus was building a bomb. Bracken is no longer the only one in danger. Now innocent people could be killed.