Ash, Professor Kukui, and Professor Burnet prepare to leave the house to go to the local shops, while Rotom Pokédex will stay behind to look after the currently sleeping Pokémon. Rotom waves the trio goodbye and uses the opportunity to snap images of the napping Pokémon. Rotom's photography session is then interrupted by the doorbell, waking Litten in the process. Rotom answers the door, finding a deliveryman and his Machoke. He is a little shocked to see Rotom and asks if anyone is home, but Rotom explains the situation. Machoke brings in a bright orange washing machine, surprising Rotom, who then signs off on the delivery and closes the door. Just then, Litten and Lycanroc get into a playful fight, taking Rotom's attention and sense of peace with it. Meanwhile, the washing machine turns out to be another Rotom. Litten's Ember hits Rowlet by mistake, and Rowlet attempts to target Litten in retaliation. Instead, it attacks Pikachu, who responds to the painful awakening by shocking everyone in the room. This sends the two Rotom flying about, before knocking themselves back into the washing machine and Pokédex cover.
Ash, Kukui, and Burnet return home to see the washing machine, just as the deliveryman returns to apologize for delivering the wrong item. The deliveryman packs the washing machine back in his van and drives off. Meanwhile, Ash and the two Professors reenter the house and find Rotom's Pokédex cover lying on the floor. Kukui takes it from Ash's hands and taps on the screen, which causes the system to reboot. Rotom emerges, but refers to itself as "Wash Rotom Pokedex". Ash notices that Rotom is acting strangely, though Kukui and Burnet think nothing of it and assume it is just a symptom of the reboot.
Meanwhile, the deliveryman has brought the other Rotom to the local Pokémon Center. Rotom is confused to find itself inside a washing machine, and wonders where its Pokédex Index is. Just then, Nurse Joy places dirty laundry inside to wash it, and pokes Rotom's eyes in the process. Wash Rotom begins to shake violently, before its door opens up and bubbles fill the Center's laundry room. Rotom is sent into a panic and escapes the washing machine through a power socket, leaving Nurse Joy confused as to why her new machine doesn't work.
Rotom travels through the power wires, though it is instantly uncomfortable and thus dragged by the electric current to Lana's house. There, Harper and Sarah are talking into a fan, while Lana is busy doing the dishes. Rotom takes control of the fan and notes that he is at Lana's house. Suddenly, Sarah and Harper begin to fight over the fan. In a bid to escape, Rotom starts flying around, though this only amuses the twins, who pursue it. Eventually, the chase ends when Rotom hits a wall and exits the appliance, before again attempting to find the Pokédex by traveling through the overhead power lines.
Rotom returns to Kukui's house, but finds itself stuck in the television set. It calls out, only to receive no answer, After flicking through some channels, Rotom exits the TV through a power socket, fearing its Pokédex shell was thrown in the trash. Meanwhile, Ash and Pikachu, along with Wash Rotom Pokédex, are in Hau'oli City when Wash Rotom takes a picture of a mysterious Pokémon. Rotom exits a street lamp and also sees Marshadow, though it is disappointed that it cannot take a picture before being reabsorbed back into the power grid.
Rotom finds itself now attached to a lawnmower driven by one of Lillie's housemaids while she sips tea and is reading outside. When it spots Lillie, it rampages towards her, though she and Snowy flee in fear. Lillie's butler Hobbes calls on his Oricorio to perform Revelation Dance to end the pursuit. The Electric attack works, as Rotom exits the lawnmower and enters back into the power system.
Next, Rotom possesses an oven in Aina's Kitchen. It soon realizes where it is upon seeing Mallow accepting MooMoo Milk from Kiawe. Kiawe says it is strange that the restaurant ran out of milk, though Mallow explains they had many orders. She rewards Kiawe with a hot pudding, only to find Rotom's door open automatically. Mallow and Steenee inspect the puddings, only to find that they are still watery and close the door. However, its springs open again, so she closes it again. Rotom moves around to get their attention, though the act only scares Mallow and Steenee out of the kitchen. Kiawe calls out his Marowak to solve the issue, and it strikes Heat Rotom with its bone. Rotom exits the oven and into Sophocles' fridge. Hoping to get Sophocles and Togedemaru's attention, it freezes them solid with its Blizzard. Rotom escapes, just as Sophocles' mother discovers her son.
Rotom concedes that it must return to the washing machine. Ash also attends the Pokémon Center to notify Nurse Joy about his Rotom's bizarre nature. Nurse Joy is instantly reminded of her washing machine, which she points to, and the Wash Rotom Pokédex says it is nostalgic. Suddenly, Rotom enters the Center and returns to the washing machine. After the Pokédex details Rotom and its forme changes, Nurse Joy believes her washing machine may have been affected. In its excitement to see Ash again, Wash Rotom sprays a Hydro Pump. Pikachu counters with Electro Ball, though Rotom fills the room with soap suds out of fear, which Ash interprets as an attack. Ash then has Pikachu use its Thunderbolt, and it shocks everyone in the process. Once again, the Rotom exit their devices, knock into each other, and reenter their original devices.
Nurse Joy starts mopping the Center clean again, while Ash knocks on his Pokédex, causing Rotom to reboot its system. Rotom is turned on and expresses delight to be back, just as the Wash Rotom starts to rattle again. Rotom explains to Ash that the two switched bodies, and he accepts the strange turn of events. Ash then explains that the other Rotom had taken a picture of a rare Pokémon, though it was deleted. Fearing it may be missing out on valuable data, Rotom flies out in search of the rare Pokémon. Ash goes to pursue it, but he slips and crushes Pikachu, who shocks everyone once again. Ash finds the Pokédex shell lying on the floor again, and fears the two Rotom have switched bodies. Unbeknownst to him, Rotom instead bonded with the Pokémon Center. Rotom is eventually reunited with its Pokédex shell after Pikachu shocks the Center.