After two weeks of constant Cog attacks by the Machine Empire, the Zeo Rangers are run ragged, exhausted by both their superhero duties and those of their normal life. Having gotten them to a weakened, sleep-deprived state, King Mondo sends down the Somnibot monster, whose lullaby spell-singing manages to exploit this Achilles heel. Can the Gold Ranger wake them in time? Meanwhile, Bulk & Skull are entrusted to guard a safe containing a valuable item for one whole day, unaware that a cat burglar has his eye on it.