Without getting too into spoilers, Gotham made the second half of Season 4 all about the passage of madness-inducing villainy from Cameron Monaghan’s Jerome to Cameron Monaghan’s Jeremiah, with both serving as inspirations for the future rise of The For-Really-Real Joker at some point in the future.
The insanely dark arc, which also featured a Killing Joke episode, is wrapping with Gotham’s version of the cataclysmic “No Man’s Land” comic storyline, which could set the stage for an even more unpredictable narrative in Season 5, and now that the creative team knows this will be the last batch of episodes, they will almost definitely craft something fans will be rave about, with Bruce Wayne possibly becoming Batman before the season’s end.