As Julien and company head back to Madagascar, their submarine runs into trouble. Mort puts on a play for Koto to cover up the captives' escape.

Julien and Maurice face a harrowing fight at gladiator school. Mort travels to another dimension. Sage convinces Clover there's still good in Koto.

Nearly vanquished by Koto's troops, Julien rallies Mort's army, the bell snails, the space chimps, Clover and other loyal friends for one last hurrah.