Rock-A-Bye Power Rangers

Rock-a-Bye Power Rangers is the thirty-first episode of Power Rangers Zeo.

Summary
The Machine Empire has been wearing down the Zeo Rangers for two weeks with constant Cog attacks. The Rangers get incredibly sleepy despite the help from the Gold Ranger.

Mondo capitalizes on the situation by ordering Klank and Orbus to create a monster that can put people and machines to sleep so they can finally be rid of the Rangers once and for all. They succeed in creating one called Somnibot, a singing robot that can put people and machines to sleep with her lullabies. Unfortunately, her singing even makes her tired too. She is sent to Earth to carry out this mission.

Meanwhile, Bulk and Skull get a case from their boss protecting a client's safe, and must remain alert and awake because a burglar plans on stealing the safe. The Rangers and Alpha 5 also begin to suspect that Billy is the Gold Ranger due to his constant disappearances.

Synopsis
The episode begins with the Zeo Rangers fighting several Cogs in Angel Grove Park. The Gold Ranger shows up, causing the Cogs to disappear. The Rangers discuss the matter before trudging back to the Power Chamber. The Machine King and Queen see the Rangers' tiredness, and Mondo says that this advantage calls for a new monster.

At the Youth Center, the teens discuss what has been happening to them, with Rocky saying that between school, fighting monsters and homework, they haven't slept well in weeks.

Meanwhile, at the detective agency, Stone informs Bulk and Skull that their latest client, an old woman named Mrs. Hufford, has entrusted them to protect her valuables for the next day. Bulk and Skull promise not to sleep on the job, while a burglar listens in from outside the entry door.

Back at the Machine Palace, Klank and Orbus introduce the royal family to Somnibot, a monster that uses her voice to put people and machines into a deep, peaceful sleep with a cradle song. Mondo, impressed at the monster's abilities despite her having not demonstrated them just yet, orders Klank to ask a Quadrafighter pilot to take Somnibot to Earth so she can use her abilities.

While flying on the back of a Quadrafighter, Somnibot practices her song, which causes the pilot to almost fall asleep. After she wakes it back up, she puts several Angel Grove citizens to sleep in the park with her song, which we find out is "Rock-a-Bye Baby". The Rangers are individually called to the Chamber by Zordon and Alpha, who inform them on Somnibot and her special powers - she uses harmonics and music to place her victims—human or robot—under a powerful sleeping spell; however, her frequency can be altered or terminated to wake up her victims, as their sleep is magically induced rather than legitimate sleep. Rocky muses that Somni's spell seems like a very good idea right then, as we can clearly see that the Rangers want to go to the dream world immediately. While Alpha seems to show concern for the Rangers, Zordon is only concerned with Somnibot being stopped "before she does permanent damage". When they morph and teleport to a nearby river to fight Cogs again, Somnibot sings her lullaby to put the Rangers and Cogs to sleep; on Klank's cue, the monster caused the Rangers and Cogs to become sleepy by singing in a very sweet and melodious manner. Becoming very sleepy/weak, Tommy Oliver calls Alpha, but the he notes that Somnibot beat them to the punch and is bypassing the Zeo Rangers' altered power frequencies that he fixed before to make them immune to Somnibot's lullaby.

Before the Rangers can fall asleep and be sent to the dream world, the Gold Ranger shows up to "tuck Somnibot in for the night". Declaring that she isn't ready to be put to sleep herself, Somnibot fires her lasers at him, but he uses the Golden Power Staff to attack Somnibot. Mondo orders her repair.

Upon her return, she is removed of her characteristic sleepiness and is much more alert, and puts Bulk, Skull, and a burglar to sleep. Klank, Orbus and Somnibot take a truck the three humans were nearby to serve as Somnibot's mobile power station.

When the Zeo Rangers get to the three's location on their Zeo Jet Cycles, Somnibot wastes no time. She attempts to sing her lullaby again to put the Zeo Rangers to sleep, while Klank increases her power output.

Back in the Power Chamber, Alpha initiates a power surge while Billy disappears. While Somnibot continues to sing the Rangers into the dream world again, they're suddenly spotted by the Gold Ranger who is ready to fight. Klank asks that she put him to sleep as well, and Somnibot sings her lullaby and this time the Gold Ranger isn't strong enough to fight its effects and he begins to fall asleep too. However, Alpha's power surge works on Somnibot and her frequency terminates, to her anger.

Somnibot then takes on the Rangers directly alongside some Cogs, however the Cogs are quickly defeated while the Gold Ranger takes out Somnibot. Klank has Orbus make Somnibot grow, so the Rangers summon the Zeo Megazord and Red Battlezord to take her on. After beating her around for a while, the Gold Ranger summons Pyramidas and the Zeo Ultrazord is formed which manages to destroy Somnibot for good.

The next day, the Rangers meet in the Power Chamber and comment on how glad they are to have finally been allowed to have a good night's sleep. Tommy then takes the chance to ask Billy exactly what has been going on with him recently given the fact he's always tired despite no longer being a Ranger, let alone his recent mysterious disappearances. Rocky however has come to his own conclusion that Billy is actually the Gold Ranger. Billy denies this, telling the others that he's been working on something that he'd rather not talk about yet and that if he was the Gold Ranger he wouldn't keep that kind of secret from them. While the other Rangers accept this, Rocky still isn't so sure.

Cast

 * Catherine Sutherland as Katherine "Kat" Hillard (Zeo Ranger I: Pink)
 * Nakia Burrise as Tanya Sloan (Zeo Ranger II: Yellow)
 * Steve Cardenas as Rocky DeSantos (Zeo Ranger III: Blue)
 * Johnny Yong Bosch as Adam Park (Zeo Ranger IV: Green)
 * Jason David Frank as Tommy Oliver (Zeo Ranger V: Red)
 * Brad Hawkins as Trey of Triforia (Gold Zeo Ranger, voice)
 * David Yost as Billy Cranston
 * Paul Schrier as Farkas "Bulk" Bulkmeier
 * Jason Narvy as Eugene "Skull" Skullovitch
 * Gregg Bullock as Detective Jerome Stone
 * David Fielding as Zordon (face)
 * Bob Manahan as Zordon (voice)
 * Donene Kistler as Alpha 5
 * Richard Steven Horwitz as Alpha 5 (voice) (as Richard Wood)
 * David Stenstrom as King Mondo (voice)
 * Alex Borstein as Queen Machina (voice)
 * Barbara Goodson as Prince Sprocket (voice), Orbus (voice), and Somnibot (voice)
 * Oliver Page as Klank (voice)

Errors

 * When Somnibot was defeated, why weren't the people in the park that she sang to sleep awakened?
 * Despite them already knowing the location of the Power Chamber by this time, King Mondo and Queen Machina do not send Somnibot there to sing Alpha and Zordon to sleep. Plus, the Rangers do not fight her in American footage at all. Why was this done?
 * In numerous American shots, Klank and Orbus were missing their spell-resistant headphones.
 * The Cogs were glowing violet or red, apparently affected by Somnibot’s spell as she was singing, but in the next shot, they were no longer violet or red.
 * In one shot of King Mondo, his crown and the gear below it were not turning.

Song

 * Go Gold Ranger
 * Somnibot's lullaby