Season 5 of "Blue Bloods" is preparing for its grand finale on CBS on Friday.

As reported by Movie News Guide, Commissioner Reagan (Tom Selleck) promoted Deputy Chief Don Kent (guest star Dennis Haybert), who was a by-the-books drug policy enforcer in the NYPD, to a two star Chief. Kent and his wife were having lunch at a restaurant where they were gunned down in broad daylight, in Episode 21 of "Blue Bloods," which aired last Friday.

The bold crime was thought to be committed by a notorious gang that specializes in violent activities, which leads Detectives Maria Baez (Marisa Ramirez) and Danny Reagan (Donnie Wahlberg) to question the gangs more ruthless member, hit-man Mario Hunt (guest star Method Man).

After this took place, Danny and A.D.A Erin Reagan (Bridget Moynahan) constantly fight over the "by-the-book" procedures Commissioner Reagan ordered in the beginning, which leaves them at odds with the methods necessary to carry out swift justice for Kent.

Baez and Reagan later convince Hector Florez (Felix Solis) to positively identify Hunt as the shooter, which he was reluctant to do out of fear for his family's lives.

Their actions though, set off a spiral of events that led to Curtis (Denzel Whitaker), who had previously worked with Linda Reagan (Amy Carlson), to carry out a hit on Hector in the hospital. He showed up with a gun and Linda was there. Two gunshots were heard just after the episode faded to black.

The atmosphere in Episode 22, titled "The Art of War," becomes emotionally charged with potentially explosive results.

TV Guide reports that one of the Reagans has been shot and the shocking season finale goes in many different directions when Danny Reagan has a hard time keeping his emotions in check while investigating the crime.

When he locates the shooter, he has a hard time finding witnesses that can help him make a case for the crime.

Be sure to tune and watch this emotionally charged and potentially heart-breaking finale episode on CBS this Friday at 9 p.m.