Blue Bloods Season 9 Episode 17 revolves around questions of loyalty.

When a drug dealer Maya and Eddie arrest claims that someone in the precinct is stealing money from crime scenes, Eddie thinks Jamie should look into it. Jamie is skeptical, but secretly works with IAB to root out the dirty cop. However, he soon gets some information that suggests that the cop they are looking for is Eddie's partner -- and he's barred from telling her about it.

Meanwhile, Frank gets a heads-up from his old partner Lenny about an article in the New Yorker that will implicate Lenny in some corrupt practices of his own years ago. After talking to the journalist, Frank is more convinced than ever that Lenny is innocent, but he can't get him to admit it or tell him who he's covering for. Lenny wants Frank to just leave him alone, but Frank can't do that.

Elsewhere, Erin and Anthony must decide how to charge a doctor who killed his terminally ill daughter by giving her experimental treatment. The doctor says he did everything he did out of love, but his ex-wife wants him arrested for killing their child.

And Danny and Maria investigate the death of a young artist from an apparent overdose. When they learn her drugs were laced with fentanyl and that her work is worth a lot more to collectors now that she's dead, they have a case for murder -- if they can find the right killer.

Watch Blue Bloods Season 9 Episode 17 online to find out what happens with all of these cases.