Remnants of Filth: Yuwu Novel Volume 4 was written by Rou Bao Bu Chi Rou with illustrations by St, and is set in "The Husky and His White Cat Shizun!" universe.

Gu Mang has emerged from the Time Mirror a changed man. With his shattered memories recovered, he sets out to distance himself once more from his erstwhile lover, Mo Xi. In turn, Mo Xi finds himself powerless against a Gu Mang who is both so familiar and yet so cruel. Regardless, if the two hope to complete their mission and return to Chonghua, they must work hand in hand to escape the demon-infested island.

Meanwhile, Mo Xi’s own experience in the Time Mirror has left him more certain than ever that some secrets still linger behind Gu Mang’s treasonous defection eight years ago. He’s determined to dig up the truth at any cost—even the cost of his own life.