Past events can fuel present problems, as the Reagans' latest cases taught them anew.
Written by co-executive producer Siobhan Byrne O'Connor, Friday's (Jan. 17) episode of CBS' "Blue Bloods," "Unfinished Business," set Danny ( Donnie Wahlberg) and Maria ( Marisa Ramirez) on the trail of Army veteran John Russelll (guest star Chad Michael Collins), who had assaulted his wife, Maryann (guest star Kelli Barrett), and taken their son Tommy (guest star Michael Capperella) from his school.
The Army, as represented by Maj. Harrison (guest star Terry Serpico), wasn't happy that Danny had started an investigation without clearing it with him first. A struggle over jurisdiction began, with Marine veteran Danny noting, "I understand protocol. I just don't like following it."
During a press conference on a weapons-selling bust, Frank ( Tom Selleck) was confronted by Betty Lowe (guest star Karen Alle n), who asked him "why I can't get justice for my daughter. And her killer is out there, and you don't care."
As she was taken from the room by officers while loudly accusing Frank of not responding to letters she'd written him about her daughter's murder, he clearly was troubled. And clearly was going to do something.
Frank demanded of Garrett ( Gregory Jbara) why he hadn't seen the letters, and Garrett declared their writer "crazy" and then handed them over. He added he felt Danny was "overstepping" in the military probe and asked Frank what he was going to do about it.
"Nothing," Frank replied, then immediately placed a call to Danny to remind him it was to be "a joint investigation." Danny's determination was reinforced when Maria showed him a drawing Tommy had made at school, depicting a man firing a gun at a woman and a child.
Returning to the base, Danny locked horns with Maj. Harrison again, asking if Russell suffered from post-traumatic stress disorder. "You already failed this guy," Danny said. "I'm just asking you to help me get him and his boy back safe."
The major contended Danny had "a grudge against the military," to which Danny replied, "I don't have a grudge. I just don't like you." The major said, "Well, then. We have found something we have in common."
Shortly afterward, hearing a recording of a 911 call Tommy had placed -- "I'm scared of my dad, I just want to go home" -- only heightened Danny and Maria's concern.
Frank visited Betty, who maintained the jailed serial killer suspected of her daughter Michelle's murder couldn't have been the culprit, since Michelle had called her earlier that night to report she was home safe. "It had to have been someone she knew, someone she trusted," she told Frank, asking him to believe in what he'd labeled "a mother's intuition."
Erin ( Bridget Moynahan) offered to re-interview an apparent eyewitness (guest star Doug E. Doug) to Michelle's killing, now in prison for a liquor-store robbery. She admitted to Frank she feared any new information could "throw the entire [serial-killer] case into question. It's a huge risk." Frank wanted her to proceed anyway.
She did, and the talkative inmate claimed a police detective had coerced him into identifying the serial killer: "I figured the police know what they're talkin' about. Right?" Frank wasn't happy about the allegation when Erin reported back, and though she worried reopening the case would lead to a mistrial being declared, she added she had gone to see Betty herself. "She's very compelling."
At home, Danny got edgy about son Jack's ( Tony Terraciano) inquiries into their family's military history for a school project. Jack was impressed that several generations of Reagans had gone to war, but Danny said sharply, "The family legacy is not combat. It's service."
Linda ( Amy Carlson) then wanted to know if Danny's anger was prompted by his current case. Though he denied it, she said, "i see what's going on with you. Just don't take it out on our son."
Back at the precinct, Danny was visited by a psychiatrist (guest star David Wilson Barnes) who had helped him in the past, and who also had treated Russell. Reluctant to detail anything at first, the doctor ultimately opined the soldier was "still operating as if he's in the middle of a war." He then asked Danny how he was doing. The cop simply said, "You know me, Doc," and moved on.
Russell's wife told Danny and Maria she was planning to divorce her spouse, and also revealed he might be staying with an Army buddy named Lyle (guest star Jeremie Harris), who denied it when the detectives went to his home. As they staked out the house afterward, Danny informed Maria he hadn't stayed in touch with the other members of his Marine unit because "I'm the only one who made it home."
The stakeout paid off when Lyle went toward his RV and admitted to the cops that Russell and Tommy were inside. When Danny entered the vehicle, though, he found they were gone -- and what seemed to be a suicide note had been left by Russell.
Frank met with Lee Douglas (guest star Jeremy Luke), the rather cocky detective who allegedly had coerced the ID of Michelle's supposed killer. "The case is solid," he assured Frank, who cast doubt on that by noting differences between Michelle's case and the other murders. He then sent Douglas on his way by informing him an Internal Affairs investigation was in his immediate future.
Interrogated by Danny about Russell's possible whereabouts, Lyle felt beholden to keep quiet because Russell had saved his life in battle. Under Danny's pressing, though, Lyle finally admitted he'd supplied Russell with a pre-paid cell phone and gave up the number.
Jack delivered his school presentation with all of his relatives present, concluding by saying, "I see my dad go to work every day, and I know he makes a difference in someone's life every day. I want to be just like him." Everyone applauded, including a tearful Danny, and discussion of the Reagans' military experiences continued at the weekly family dinner.
Back in pursuit later, Danny and Maria picked up a signal from the cell phone Russell had, eventually tracing it to a building where he and Tommy were perched on the edge of the roof. The detectives went up and approached cautiously, telling Russell, "We're here to help you."
They succeeded in coaxing Tommy to safety, and as he left the scene with Maria, Danny continued to try to talk Russell down. The soldier reasoned things would be better for his loved ones "if I jump," and despite Danny's promise to continue to help him, Russell -- who admitted to survivor's guilt after losing several friends in a firefight -- gave a farewell salute and tipped backward off the building to his death.
That night, the psychiatrist silently brought coffee to a grieving Danny, while Frank went to see Betty again to ask her to give up her probing. He explained that reopening the case could result in setting the serial killer free and causing more pain for the other victims' families, something Betty agreed she didn't want.
Frank promised her an internal investigation of Michelle's murder would continue, adding if any new information resulted, she would hear it "directly from me."
Most of the Reagan men awoke early to leave on a family-tradition camping trip, including first-timer Jack. On the way out the door, Frank asked Danny about his report that claimed Russell "slipped and fell," and Danny explained he didn't want Russell's son growing up thinking his father was a suicide. Frank agreed to keep the secret. Â
Photo/Video credit: CBS