Blue Bloods featured a case that entangled all the Reagan siblings, but it was Erin's part of the story that led to a surprise at the Reagan family dinner in the end. The case started when Eddie found a gun in the backseat of a car and wound up involving the attempted murder of a person in witness protection, a crime family, and none other than Jack Boyle, Erin's ex-husband. The episode, titled "Happy Endings," was the first appearance of Peter Hermann as Erin's ex in Season 11.
After Eddie (Vanessa Ray) discovered a gun in the backseat of a car she stopped, the passengers - Andrew Miles (Jimi Stanton) and Charles Hayes (Eric Tabach) - were arrested. During the arraignment, Miles was released on his own recognizance while Hayes was held on bail because Miles claimed the gun was his friend's. Hayes' public defender was incompetent, and Erin (Bridget Moynahan) just happened to notice Jack was in the audience. Erin later asked Jack to represent Hayes to give him a fighting chance during a trial. Jack agreed to do it, but only if she would agree to a romantic getaway weekend with him if he proves Hayes was innocent. Erin said if Hayes was convicted, Jack would have to go to a Reagan family dinner.
While this was going on, Danny (Donnie Wahlberg) and Baez (Marisa Ramirez) investigated the attempted murder of John Romano (Jim Santangeli) and his girlfriend. They discovered Romano was actually in witness protection and was secretly taking trips from Oregon to New York, even though this put his life in danger. This was connected to the Miles-Hayes situation because the bullet in the attempted murder matched the gun discovered in their car. During their investigation, Danny and Baez discovered that Romano's ex-wife posted on Facebook that she would reveal Romano's location to anyone with a grudge against the man who testified against his fellow criminals.
Only one person actually took up Romano's ex-wife on her offer. Someone with the name of Hayes, she told Danny and Baez. Things were not looking good for Hayes. But the DNA from the trigger matched Miles. That should have been good news for Jack, but he told Erin that Hayes was actually ready to take a plea deal.
Why? Hayes was ready to go down for his friend, but Danny and Baez discovered quickly that Hayes didn't have to. They discovered that Miles' real father was killed by Romano as a mob hit, and Miles used Hayes' Facebook profile to contact Romano's ex-wife. Miles got a gun and hoped to kill Romano, but only injured Romano. Later, Jack told Erin that Hayes revealed Miles was going to pay him off if he said the gun was his. Jack was ready to take credit for Hayes not going through with this, but Erin reminded him that it was really Danny and Baez's detective work that did the job.
However, Jack reminded Erin that he did win the bet. He said he would not hold her to it, but Erin said she has never broken a promise. Erin had a grin from ear to ear as Jack left her office. Then at family dinner, she brought Jack in with her. Their pie from Pennsylvania proved that they really did go on that romantic getaway.
Although the other Reagans made it very clear they still do not like Jack, they welcomed him to the table. Everyone had to be on their best behavior... including Jack, Frank reminded him. Jack sat down next to Danny, across from Erin. After Jack accidentally revealed that they went on a romantic weekend, Erin said Jack didn't have to come to dinner, but he chose to. "I can take the heat," Jack told Pops (Len Cariou). They then asked Jack to say grace, just before the episode ended. It is not clear if Jack will be in a future episode, but if he is, there will definitely be some more romantic tension between him and Erin.
The episode also included an important scene between Eddie and Erin, which is a rarity for the show. Eddie wondered how Jack and Erin's relationship fell apart. Erin said they focused on their flaws "instead of what made their love special." She told Eddie she didn't have to worry about this with Jamie (Will Estes) because they wouldn't let that happen. This inspired Eddie to prepare a romantic dinner for Jamie. Eddie shared her concerns, but Jamie assured her their love was strong enough to overcome small squabbles at work.
Blue Bloods airs Fridays at 10 p.m. ET on CBS, but there is a repeat on Friday, April 23. You can stream past episodes on Paramount+. Disclosure: PopCulture is owned by CBS Interactive, a division of ViacomCBS.