"I deliver everything that the post office service does not handle." Eun-ha, who is a normal junkyard employee, secretly works as a delivery clerk that deals with unusual delivery requests.

An unfathomable incident introduces a genius engineer to dangerous secrets of the world — and to a woman from the future who's come looking for him.

One by one, the crafty members of a destitute family insinuate themselves into the household staff of a wealthy couple living in oblivious privilege.