The DC Multiverse has faced many a crisis, time after time... after time. In fact, on more than a couple of occasions, the very fabric of existence upon which the realities within DC's comic lore are built has unraveled. But in the end, the Justice League usually rushes in to save the day.
In the wake of the events of Dark Nights: Metal and Justice League: No Justice, we learned of a breach in the Source Wall, the very border of the universe, which is now leaking cosmic energy, resulting in a death sentence for the Multiverse.
But for some reason, even with the Multiverse confirmed as dying in Justice League #1 from Scott Snyder and Jim Cheung, the League doesn't seem to be stressing about it... which is an odd reaction, to say the least.
In No Justice #4, we saw the entire Green Lanterns Corps trying to plug the Source Wall breach. However, even the combined power of their rings simply wasn't enough. And so, in Justice League #1, we see a dose of energy called the Totality exit the breach and begin its journey towards Earth.
As the League assesses this, though, it appears not all of them are convinced this is a Multiverse-ending issue, which really and truly isn't a gamble they should be taking. These heroes are usually proactive, but here, even with the all-planning Batman in the mix, there appears to be a surprisingly nonchalant, and dare we say lackadaisical, attitude about things, as though the Multiverse's death is a problem for another day.