Hijikata and Sougo find themselves chained to each other in a strange place. After they remember how they got there, a mysterious man shows up in a t.v. attached to the wall. The man tells them that if they can't get the key, which unlock their chains, in 72 hours the Shinsengumi headquarters will explode by a bomb placed within it. The catch is if one escapes and unlocks their chain the other person will explode.
- This arc is a obvious parody of the Saw franchise.