Thousands of worlds behind the door

Lin Mo, an ordinary junior in the Physics Department, stumbles upon an unusual secret: the innermost stall door in the dormitory’s public restroom leads to four entirely different worlds. The rust patterns on the door handle shift depending on which world is connected—appearing as a sword, an ancient tripod, a broken wall, or a mysterious rune. Each world operates under its own distinct set of rules, and the knowledge and abilities Lin Mo brings back with him begin to subtly transform both his once-ordinary life and the world around him.