Mad scientist, Hyukjae, is on the brink of making a scientific breakthrough: time travel. But what he didn't expect was a boy from ancient times popping up in his lab. Heechul had warned him about screwing up the universe— maybe he should’ve listened.

It’s the middle of the summer and the city is facing its worst heat wave on record. When the air-conditioning unexpectedly gives out, Donghae and Hyukjae have to find some way to stay cool.