Great news if you're a Joe Hill fan: Joe is back!

His last appearance was bittersweet as he and Frank butted heads over investigating the vandalism to Joe Reagan's gravestone. Joe stormed out of the Sunday dinner after learning Frank hadn't told anyone about the desecration of their brother's grave.

Joe's relationship with Frank is unlikely to improve on Blue Bloods Season 13 Episode 13, as Frank has to weigh options for disciplining him on the job.

Frank is no stranger to separating his work and family life. The other Reagans are used to it; they know that Frank won't give them special treatment or go light when they screw up on the job.

Joe didn't grow up with Frank and is unsure of his place in the family. So if he gets in trouble with Commissioner Reagan, he'll see it as another indictment of him as a Reagan by the family patriarch.

21 Characters Who Work Way Too Hard

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Frank's attitude is the right one. He has to treat all the cops under him the same, and there are clear guidelines as to what police protocols are and what happens if an officer breaks them.

In the current climate, where many people are looking for proof of police corruption everywhere, Frank can't afford to go easy on any cop, especially one related to him. The last thing his office needs is nepotism accusations by anti-police activists.

It's not in Frank's nature to do that, anyway.

Joe Hill tends to be stubborn and oversensitive to Frank's criticisms. He's likely to think that whatever rule he broke was no big deal and resent Frank for enforcing it.

Joe's grown to respect Jamie and Danny. They aren't close, but he has somewhat of a relationship with both of them, especially Jamie.

Hopefully, one of them can help him understand Frank's perspective so he doesn't cause more Sunday dinner drama -- or boycott the family meal all together.

How receptive anyone is to this depends on what Joe's transgression turns out to be. He's working on a joint task force with the FBI, so it could be anything from sharing private info with the press to refusing to allow an FBI agent to take over his case.

Danny probably won't be in the mood to help despite his history of rebellious behavior. He and Baez are racing against the clock to catch a serial killer who wants to strike again.

Serial killer stories are always hit or miss on any cop show. They are among the highest-stakes crimes a cop can investigate. Until the killer is caught, countless people are in danger, and the detectives often feel pressure to catch the killer before they strike again.

Still, the serial killer who leaves cryptic messages for law enforcement has become such a common trope that it often wears out its welcome. It's especially annoying if the killer kidnaps someone important to the lead detective to further up the stakes.

Blue Bloods isn't strictly a crime drama; it's about how the cases affect the cops and how the Reagans support one another, as it is about solving the crime of the week.

We can expect this case won't get overly graphic or gory, which is a plus, and that Danny will get his killer in the end, possibly with help from other Reagans.

Eddie's got a more extensive story this week! She and Erin butt heads over what Erin sees as interference in her professional and personal lives.

Erin is supposedly leaving investigative duties behind to focus on her campaign, but first, she's working on a murder trial, and she doesn't want Eddie involved.

Whatever's going on involves Jack. Erin rejected his friendship because it wouldn't look good for her campaign, but will Eddie convince her to give Jack another chance?

Erin won't want her sister-in-law putting her nose into this long, complicated relationship. She barely tolerates Anthony getting involved in her dating life -- why would she accept it from Eddie?

How does Eddie get involved in this case, to begin with? If she's the cop who made the collar, it makes sense. Otherwise, she's minding Erin's business, and Erin is right to push back on that.

Jamie and Eddie rarely have scenes together nowadays, which is a shame because they are Blue Bloods' only solid couple. Danny's widowed, Erin's divorced, and Frank and Henry have no interest in finding new partners at this late date.

So we're left with Jamie and Eddie (and some viewers' fantasies about Danny and Baez!), but they seem to inhabit separate worlds now that they're married.

This time might be an exception. If Erin and Eddie are fighting, Jamie's forced into the middle of their conflict.

If nothing else, it'll make for a tense Sunday dinner, as if Joe and Frank's problem doesn't already guarantee enough drama there!

Frank has a rule about no fighting at his dinner table, but will anyone follow it? And will Anthony put his two cents in with Erin throughout the hour, making things worse instead of better?

What do you think, Blue Bloods fanatics? Hit the big, blue SHOW COMMENTS button, and let us know your thoughts about these spoilers. And don't forget you can watch Blue Bloods online while waiting for the new episode to air.

Blue Bloods airs on CBS on Fridays at 10 PM EST / PST.