Bungo Stray Dogs, Vol. 4 (light novel)

The Armed Detective Agency’s latest case brings them to the floating city Standard Island, a strange man-made vessel and a resort for the wealthy off the coast of Yokohama. But what awaits the detectives turns out to be far more complicated than any of them could have expected: a bomb, time travel, a mysterious skill user named H. G. Wells…Will this case spell the end of Yokohama itself.