8 Mysteries Even Batman Couldn't Solve

Released throughout 1996 and into 1997, The Long Halloween is a landmark, benchmark story that forces the World's Greatest Detective to live up to that particular moniker. The thing is, while Batman deduces that the mysterious Holiday Killer of the tale is actually two people, the Caped Crusader doesn't seem to realise that there was a third person behind the murders of this tale.

In The Long Halloween, Holiday strikes on each public holiday, fatally shooting a new victim each and every month. While this very much features a who's who of Batman's rogues' gallery, the story also plays out in the backdrop of a raging war between the Falcone and Maroni crime families.

As part of the same war, District Attorney Harvey Dent winds up with acid thrown into his face in a move that sees him become the nefarious Two-Face. And while Harvey is rightfully pinned as Holiday, it's similarly worked out by Batman that Alberto Falcone - the runt of the Falcone family - is also Holiday.

What's shown in the final panels of The Long Halloween, though, is that Dent's wife Gilda was another who portrayed Holiday, with her responsible for the initial few murders as part of her plan to ease the pressure on her husband so that they could start a family. Where Gilda is concerned, Batman never picked up on her being the third wheel of the Holiday puzzle.