The carnival parks beside the board for 4 of your turns. After every move by either side the wheel spins a minor act: a random pawn wanders sideways, a random piece naps for a turn, a random square is roped off for a turn, or confetti falls and nothing happens at all.
You draft Pandemonium Carnival in either mode. Passive: it works on its own the whole time you hold it, with nothing to activate.
As a item card, it is a one-use consumable, drafted in either mode.
“The calliope is load-bearing.”