At a run-down hotel, a timid desk clerk named Yolton shows our heroes to their room. Satoshi wants to check out the hotel's public battlefield, where they discover Mantle, the owner, challenging other Trainers to battle and taking their Pokémon when they lose. Yolton's Rotom comes out of hiding to reveal that its Trainer was once the owner, but Mantle challenged him to a battle on the hotel's opening day 10 years ago. When the inexperienced Rotom ran away, Mantle declared himself the winner--of the battle and the hotel. To make amends, Rotom sends our heroes back in time to that fateful battle. This time, Citron and the others help Yolton and Rotom defeat the crook. When they return to the present, our heroes discover a big change: the hotel is sparkling and clean, Yolton is the rightful owner, and Mantle and his goons are working as bellhops. And a framed photo from the hotel's opening day proves that our heroes really were there.