S3E13: Fireworks Cabin

At nightfall, just as Grizzy starts to doze off, a racket comes from outside the cabin: the Lemmings are sliding along the Great Wall in a crate, propelled by firework rockets. Cleverly avoiding the bear's strategies to stop them, the Lemmings accidentally set off a mechanism in a tower. A secret room filled with cannons and catapults opens, just waiting to be used by the powder monkey apprentices…