Ok... watched it. Here's my summary of the ep:
Starts with Ash and Pikachu on a rock formation on the water's edge, psyching themselves up for the Hoenn League. The rest of the gang are watching the two, with the usual commentary. Then out of nowhere, Drew with his Masquerain appear on another rock formation, just as a huge wave comes in. Brock tries to warn Drew, but Drew orders a Silver Wind, and Masquerian launches the attack on the wave, breaking it up before it hits. Everyone's impressed with the power of the attack.
The group meets up with Drew to remark on the attack. Drew remarks its nothing, as he's getting ready for the Grand Festival. Drew asks about May's collection of ribbons, and May shows him her four ribbons. Drew then shows May his five ribbons, the number needed to get in the Grand Festival. After a little "rubbing it in" May and Drew are facing off against each other, with Beautifly and Masquerain. They start battling, but Team Rocket interrupts when they crash ashore with their Magikarp sub. TR says a few lines of their motto, then turns on a vacuum to suck Pikachu into the sub. Unfortunately, the vacuum is too strong, that it sucks everyone on the beach. The group ends up into the control room(the room where TR pedals to power the sub) and onto TR. Wobbuffet pops out and startles Max, which causes Max to hit a button on the wall, activating some powerful jets that sends the sub blasting into the water. The sub hits a whirlpool, which then explodes and sends everyone flying and scattered over an island surrounded by mists.
Team Rocket is the first to recover from their fall. They find out that Wobbuffet is missing(accompanied by some imitations of Wobbuffet by James and Meowth).
Elsewhere on the island, Ash, Brock, Max, and Pikachu get themselves together. Seems May and Drew are missing, so they strive to search the island for them.
May and Drew are at the island's edge, watching the whirlpools that surround the island. Then out of nowhere, a motorboat with an old man piloting it comes through the mists. The old man comes up to the two and explains to them they are on Mirage Island. Drew is astounded, and May ask why. Drew explains that the rare Liechi Berry grows on this island, and it's a good berry for Pokeblocks. The old man say's he'll lend his assistance on friending their friends.
Back to Ash's group, Brock is finding out that his compass is no good, as the needle is poiting everywhere and not stopping. Swellow flys to the group, shaking it's head as it has not found May. Ash and Brock decide to uses a different tactic, using Corphish and Mudkip.
As for Team Rocket, Jessie is frustrated that she can't find Wobbuffet, until she hears a soft cry from a Wynaut. Thinking it's from Wobbuffet, she follows the sound.
As for Drew and May, that are listening to the old man's tale on how he found the island as a young man, while standing on a river's edge. Drew then spots a plant with the rare berries. He and May both run up to the plant, but the edge is unstable, and both of them fall. The old man calls out his Bellspout and commands it to use Vine Whip to rescue them. May grabs on to the Vine Whip, then Drew, but she can't hold on. They both fall in the river, and down a waterfall, which knocks Drew out. As May struggles to keep Drew's head out of the water, a bunch of Wynauts come to their rescue.
Ash's group find themselves at the waterfall, with the old man calling out to them. The old man explains the situation. Now the group knows they have to follow the river.
Drew wakes up to find himself in a cave with May and a bunch of Wynauts, with the May explaining how the Wynauts rescued them. A Wynaut walks up to them with a couple of Liechi Berries. Both coordinators take one and bite into them. They are surprised by the taste(as in, 'blah!').
It is now nighttime, and Team Rocket has not located Wobbuffet. However, Wobbuffet has appeared, eating a bunch of Liechi berries. Team Rockets ask where Wobbuffet got the berries and Wobbuffet points. Team Rocket rushes off to get their prize.
Back in the cave, May has apparently decided to wait it out by playing with the Wynaut along with her Pokemon.
Team Rocket has now found the Liechi berries, and pick one to eat. They soom discover how it tastes. Meowth notes that while the berries aren't exactly good eating, they make good Pokeblocks.
May is still playing with the Wynauts, when suddenly the group hears a vacuum. It's Team Rocket in a Wobbuffet balloon, with a vacuum attachment to suck up the berries. However May gets sucked up as well. The balloon floats away to get away from Drew, but Drew with the help of the Wynauts manage to follow.
As Team Rocket sucks up all the berries on the island, May stuggles in her bonds as TR has tied her and hung her on a tree branch. She can't reach her Pokeballs, but then she sees Drew coming to the rescue.
At the cave, the group finds that it's empty. The old man notes that the plans here seems to be stripped of berries. Ash remarks it's the work of Team Rocket.
Jessie sends in Seviper and orders a Poison Tail. Drew calls out Roselia and orders a Magical Leaf. Seviper blocks Roselia's attack with its tail, and continues on with its attack. However, a counter by a Wynaut causes Seviper to hit itself with its own tail. Drew then orders a Petal Dance, and Jessie asks Wobbuffet to block the attack. But it turns ot the attack was to free May from her bonds. Jessie orders another Poison Tail, but before it can attack, Seviper is hit with a Thunderbolt. Ash's group has arrived.
Jessie and James call out for Dustox and Cacnea to even the odds. Dustox attacks with Poison Sting, but Drew calls out Masquerain and orders Silver Wind to block. James calls out for Pin Missle, and Meowth fires a futuristic cannon to power up that attack. But its block by a group of Wynaut forming a wall. Ash tells Pikachu to use Thunder, and the attack fries the balloon and separates the attachment containing the berries. May and Drew then orders Beautifly and Masquerain to use Silver Wind, which blasts Team Rocket into the horizon.
The episode ends with the old man taking the trainers on his boat back to the other islands, as well as giving May a present a basket full of Liechi berries.