Blue Bloods Season 10 Episode 15 revolves around Frank's relationship with an old man he's known since childhood.

Mr. Kay calls Frank because a new law allows the guy who stole a bunch of stuff from him return to the apartment. He rejects Frank's offer to get him out of there because he is agoraphobic and in a wheelchair.

Frank is upset and explains to Abigail how important Mr. Kay is to him. When he was a kid, he was getting into trouble and Mr. Kay gave him a job and got him on the right path. Now he doesn't know how to help him.

Frank tries to encourage Mr. Kay to go out, but Mr. Kay gets scared and tells Frank to go away.

Meanwhile, Jamie is in trouble when a perp is caught who is wearing a cop's bulletproof vest -- and the vest is Jamie's. He tries to do his own investigation, which gets him in more trouble.

And Erin has to decide what to do when a gangster promises info on corruption in the DA's office in exchange for a lighter sentence, while Danny and Baez investigate the murder of a guest in a high class hotel.

To find out what happens, watch Blue Bloods Season 10 Episode 15 online.