CBS's "Blue Bloods" Season 10 remained as gripping as ever, with riveting crime scenes and personal challenges making for an intense watch. Patriarch, Frank Reagan (Tom Selleck), struggled with the new mayor's teamwork issues, while Erin Reagan (Bridget Moynahan) tried balancing work stress and her daughter's relocation. Meanwhile, Jamie (Will Estes), Eddie (Vanessa Ray), and the rest dealt with myriad professional and personal issues. Amidst these struggles, several deaths occurred, casting a shadow over the characters' lives. Season 10’s most tragic event, however, was the death of an undercover cop. In the episode "Fog of War," Danny (Donnie Wahlberg), Baez (Marisa Ramirez), and Texas Ranger Waylon Gates (Lyle Lovett) are tackling a Lone Star Killer investigation, as Eddie and Officer Addison (Justin Cunningham) get caught in a shoot-out. Addison mistakenly shoots an undercover cop, resulting in a tragic loss that sends shockwaves across the department. The grief spills over when Eddie gets into an unanticipated fight at the precinct, leading to Frank stepping in to remind everyone to honor their fallen colleague respectfully.