As our heroes and their Pokémon enjoy another fine meal prepared by Brock, Golbat begins to act strangely and flies away. Brock, Ash and Misty chase after the Flying-type and end up at an archaeological dig. When they meet the intelligent and beautiful archeologist, Tierra she explains her ultra-sonic equipment had just been destroyed and perhaps its errant waves attracted Golbat. She also tells our heroes of an ancient golden mask and scepter, once belonging to a queen who had the power to control all Pokémon. She is now looking for a buried temple said to contain these two priceless artifacts and asks Brock if his Golbat will use it's Sonic attack to help her locate the exact placement of the temple. Overhearing our heroes, Team Rocket employs their latest mechanical menace, the Dig-a-Tron to beat the gang to the temple. When Jessie dons the mask and scepter she has the power to control all Pokémon, even Pikachu! What will become of the Pokémon under Jesse's rule?