Rock-A-Bye Power Rangers

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 creating Somnibot, who can put people and machines to sleep with her lullabies. She is sent to Earth.

Meanwhile, Bulk and Skull get a case protecting a client's safe, and must remain alert because a burglar plans on stealing the safe. The Rangers also begin to suspect that Billy is the Gold Ranger.

Synopsis
The episode begins with the Zeo Rangers fighting several Cogs. 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.

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. Mondo, impressed at the monster's abilities, 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. The Rangers are called to the Chamber by Zordon and Alpha, who inform them on Somnibot. 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. Becoming very sleepy, Tommy Oliver calls Alpha, but the little robot 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 sleeping song.

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 goes off to do something else. While Somnibot continues to sing the Rangers into the dream world again, they're suddenly spotted by the Gold Ranger. Klank asks that she put him to sleep as well, and this time the Gold Ranger is affected. However, Alpha's power surge works on Somnibot and her frequency terminates, to her anger.

Cast

 * Catherine Sutherland as Katherine 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 Gold Ranger (voice)
 * David Yost as Billy Cranston
 * David Fielding as Zordon
 * Bob Manahan as Zordon (voice)
 * Donene Kistler as Alpha 5
 * Richard Steven Horwitz as Alpha 5 (voice) (as Richard Wood)
 * Paul Schrier as Bulk
 * Jason Narvy as Skull
 * Gregg Bullock as Det. Jerome Stone
 * 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 that she sang to sleep awakened?
 * Despite them already knowing the location of the Power Chamber, King Mondo and Queen Machina do not send Somnibot there to sing Alpha and Zordon to sleep.

Song

 * Go Gold Ranger
 * Somnibot's lullaby