Gotham returned from hiatus, but its protagonist, Jim Gordon, is barely featured in the April 24 episode. While Lucius Fox stands in for Jim as Harvey's partner — outwitting Edward Nygma without once brutalizing a suspect in questioning — Jim spends most of the episode speaking with his uncle Frank Gordon. He hasn't seen Uncle Frank in years — not since the death of Jim's father and Frank's brother, Peter Gordon. By the time the episode is over, Jim joins the Court Of Owls, or he's at least considering it despite everything he already knows about the group of of wealthy Gothamites. If you think back to Season 2, Jim didn't quite learn everything about them. But he is close to Bruce, who has seen that this cabal controls all of the businesses in the city, including his.
But when it comes to the Gordon family, they seem to eventually wind up doing the right thing. So of course, when Frank invites Jim Gordon to join the Court Of Owls in order to supposedly avenge his dead dad and break the Court apart from the inside, Jim can barely resist the idea. Even when Frank is earnestly pleading with Jim at his kitchen table, Jim's justification feels like a bit of a reach. Everything that Jim knows about the Court so far — like the fact that they were behind Hugo Strange's entire lab — would suggest that joining them wouldn't necessarily do anything to take them down.
But, all of the arguments and persuasion are revealed to have just been a trick on the part of Frank, who is still invested in the Court (or running a very elaborate scheme of double and triple-crosses). But here's the next big question: what value could Jim possibly have for the Court? At one point, he had a really good connection with Bruce Wayne, but the Court just kidnapped Bruce and replaced him with a doppelgänger, so it would make more sense to keep those two as far apart as possible.
Whatever Frank and Kathryn want with him, Jim is motivated by revenge. And though danger lies ahead, the prospect of avenging his father may prove irresistible to the Gotham cop.