I Copied the actual synopsis from SciFi.com. Here it is:
[ 4.17 ] “Dutch Treat”
Without the key, Stan is unable to command the Lexx to eat, so it is slowly starving to death. The Lexx begins consuming its own flesh in an attempt to stay alive, endangering the structural integrity of the ship. Fearing that Lexx will break apart, Stan, Xev and Kai deduce that the Noah, Ernst Longbore’s ship, might be their only way out of the solar system. They head down to Earth in a moth but leave 790 behind since they are tired of the robot head betraying them.
Priest, Bunny and Prince (on the TV) board the Lexx hoping to steal away with it, but they soon discover Bunny no longer has the key. They deduce it was lost on the Lexx when Bunny and Priest engaged in some hanky-panky. Figuring it must once again be in a moth breeder, they embark on another killing spree. Bunny recaptures the key and orders Lexx to blow up the Earth. Lexx fires a destructive beam, but the ship is so weak that it is only able to blow up Ottawa. To regain its strength, Bunny commands the Lexx to eat Holland.
Meanwhile, Stan, Xev and Kai learn that Longbore has no intention of bringing them along in his newly built ship. He plans to take with him a bunch of attractive women instead. They return to the Lexx and stop Bunny from blowing up the Earth. Stan recovers the Key when he interrupts a love session between Bunny and Xev. Kai takes the TV with Prince on it out in a moth so he can crash it into the moon and finally do away with Prince forever.