Detective Comics Vol. 1 (1937-2011; 2016-) #880

Plot

It all comes down to this! The Joker is on the loose in the catacombs beneath Gotham City, more vicious and frightening than ever. But even as Batman closes in on The Clown Prince of Crime, he begins to suspect that the city may be the target of an even deadlier threat — one that could shake Gotham City to its core.