After an unlikely confession, Nira vows to find the truth. But the group’s hunt for clues only makes the suspect look guiltier, until Chris finds new evidence.

As the team races against a ticking clock to uncover Question Mark Face's true identity, Emi begins to suspect Sam's secret crush, setting their relationship ablaze.

With one final clue, the group unmasks Question Mark Face. But when they discover their motive, the friends realize the problem is deeper than they thought, and it's up to them to make things right.