A rundown of this week's Blue Bloods installment:

- Sammy Kahn an NYPD undercover intelligence officer is shot in Central Park.  He was investigating a possible terrorist attack but the exact target is unknown.  NYPD needs to know if his cover was blown.  If so other officers lives may be in danger and they will need to be pulled from the case.

- Frank puts Danny in charge of the investigation because he knows he can trust him but Danny is unable to tell his partner that the shooting victim is really an undercover cop.

- Danny and Jackie find the motorcycle used in the attack.  The owner says his roommate Raheem used the motorcycle and shot Sammy but he doesn’t know why.  They then track down Farrah, a woman who called Sammy frequently.   She and Sammy were close friends.

- Farrah goes undercover and gets Raheem to confess that he shot Sammy because he was jealous.  Sammy’s cover is intact and the undercover investigation continues, stopping a bio-terrorism attack against the city’s water supply.

- Jamie and Renzulli are called to a rich, young woman’s home.  Melissa believes someone has been breaking into her apartment and moving things but not taking anything.  Renzulli thinks she’s crazy or making it up to get attention but Jamie believes her and catches her brother breaking in.  The brother was cut out of the will.  If he made Melissa look crazy and declared incompetent, as next of kin the money would go to him.

- Detective Molevsky reminds Jamie that he worked on the Warrant Squad with his brother Joe.  In a loosely veiled threat, he reminds Jamie that “it can be dangerous out here.”