It's a good day to be a fan of DC Comics' universe-restarting Flashpoint event, because as challenging an enemy as Reverse-Flash turned out to be, it was an alternate universe hero Barry Allen was fighting for the series spotlight. Of course, that's to be expected when you're sharing cover space with an even darker and grimmer take on Batman (few would have thought that possible). And with the Flashpoint Batman's existence being alluded to at the very start of DC's "Rebirth," fans had reason to hope the character could make some kind of appearance. They'll be getting their wish... and then some.

DC is continuing to market its upcoming Batman/Flash crossover story "The Button" which will be delving into the larger "Rebirth" mystery, beginning with the Watchmen button that first revealed the true architect of the New 52 (Doctor Manhattan). Barry Allen and Bruce Wayne are combining their detective skills to track that mystery back to its beginnings in Flashpoint. Judging by the newest cover art for the series, Thomas Wayne is set to return... and his son, Bruce, is about to meet him.

For the unfamiliar, the 'Flashpoint Batman' as he is now called was none other than Thomas Wayne, thanks to a cruel twist of fate. In the catastrophe-filled "Flashpoint Universe," it was only Bruce Wayne shot to death by a gunman in Crime Alley. Thomas was tormented and created a darker, more extreme Batman as a result. So when Barry Allen needed to set history right, Thomas was all too eager to help, if it meant recreating a world where his son survived. The plan went off without a hitch, and Thomas and Barry agreed to test the rules of reality by writing a last letter from father to son, delivered by speedster.

"The Button" is the next installment of that particularly chapter of The Flash and Batman's history, and the official synopsis warns that it could hold perils of its own:

Two greatest detectives in the DC Universe unite to unravel the mystery behind a certain blood stained smiley face button stuck in the Batcave wall. However, what begins as a simple investigation soon turns deadly when the secrets of the button prove irresistible to an unwelcome third party — and it’s not who anyone suspects! This is a mystery woven throughout time, and the countdown starts here!

That button's resemblance to the letter in terms of multiversal radiation will likely prove to be the lynchpin of this entire mystery. It remains irrefutable proof of parallel timelines and universes, and as such was studied by Batman before discovering said Watchmen button back in DC Universe: Rebirth #1. With Jason Fabok's artwork for Batman #22 now released, it sounds like Batman and The Flash may not be digging into a what, but a who.

The cover depicts Flashpoint Batman (Thomas) standing over the bodies of his son, Bruce, and wife, Martha. Variant artwork by Tim Sale for the issue - the third chapter of the story - depicts both Flashpoint Batman and the normal Batman standing together, seeming to confirm that the two Wayne men will finally cross paths. Expect plenty of tears for devoted fans... and looking at the comic image a bit closer, a lot of questions, too.

In the original Flashpoint timeline, Thomas and Martha both survived the attack. Thomas turned to dark justice as the Batman, but Martha followed a more twisted path, cutting her cheeks into a bloody smile and murdering the shooter (Joe Chill) with a hammer. It was a playful way of confirming that Martha became the Joker to this particular Batman, but this image suggests another outcome - an alternate, alternate take on the Wayne Family tragedy.

Is Thomas Wayne's Flashpoint Batman the "unwelcome third party" mentioned in the synopsis? Prior artwork implied it was only Reverse-Flash returning to the DCU in pursuit of trouble, but perhaps it's a killer caped crusader who's actually the one to be feared. And if Bruce Wayne is brought face to face with a different version of his father than the one who sent the letter, is that for the better, or worse?

Time will tell. But strange days for Bruce Wayne are coming fast.

NEXT: DC's 'The Button' Returns Jay Garrick & Reverse-Flash

Batman #22 arrives on May 2, 2017.