I am missing a certain part of the Joker timeline that has seemed to elude me no matter how many of his comics I read. He seems to be in countless crossovers, so I'll never find them all.

At one stage Joker went to the slab. This was where Joker had a whole army of Jokerites storyline. That prison he was at held multiple metahumans and freaks.

My problem is I've never seen any storyline as to why he left that prison. In some of the modern comics he's just 'there', randomly sprouting up, like in Hush or City of Crime.

Anyone have any idea?

I believe the Slab was closed after the massive jailbreak orquestated by Brother Blood during Outsiders.

Joker showed up in Outsiders before the whole Brother Blood thing, so he didn't escape during that jailbreak. But it's been a while since I read Winick's Outsiders, so maybe they did give an explanation.

We try to forget that monstrosity of a storyline called "emperor Joker"

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