You find the Plasma Frigate moored east of Seaside Cave. With Marlon's help, you and Hugh can board the Frigate.
Board the Plasma Frigate
Walk up the gangplank that Marlon put on the ship and go on board the Plasma Frigate. As soon as you enter the ship, Hugh will tell you to battle the nearby Team Plasma Grunt. He sends out a level 46 Watchog, followed by a level 46 Garbodor.
After the battle, the Team Plasma Grunts will run off. Hugh will go toward the front of the ship saying that Zinzolin came from that direction when you saw him in Driftveil City.
Before you follow Hugh, go to the right side of the ship and then go straight down, then up some stairs to find TM67 Retaliate. Then go all the way to the north end of the ship and up the stairs to find a Revive.
Go back down the stairs and go to Hugh, who is near the north end of the ship. He will go inside and you will follow him. The two of you will battle two Team Plasma Grunts. They start with a level 46 Seviper and a level 46 Golbat. After that, they send out a level 46 Drapion and a level 46 Garbodor.
After you and Hugh defeat the grunts together, the next part depends on which game you have.
Lower the Barrier
In Pokémon Black 2, Hugh will say that you have to deactivate the barrier up ahead by finding the hidden switches. In White 2, Hugh will say that you need to deactivate the barrier by inputting a password. Use the south exit of the room that has the barrier in it. Then go down the stairs across from the door that you came out of.
Down here, you meet an ex-Plasma spy. There are two real Plasma Grunts on the left and right who are patrolling the area. If you battle them, the one on the left uses a level 47 Krookodile, and the one on the right uses a level 47 Drapion.
The layout of this area is slightly different in the two versions. Here is what you find if you're playing Black 2.
There are six doors in this room. The top-right room leads to a Plasma Grunt who doesn't fight you, but instead tells you to use the beds to heal up. There is also a Magmarizer in this room.
The middle left room leads to a Plasma Grunt who adds Reshiram and Zekrom to your pokédex.
Go to the top-left room and use top-left transporter, then step on the red switch and go back. The Grunt at the bottom of the top-left room has a level 47 Garbodor. The Grunt in front of the top-left transporter has a level 46 Whirlipede and a level 46 Watchog.
Go to the bottom-left room and use the top-left transporter, then step on the red switch and go back. The Grunt in the middle of the bottom-left room uses three level 45 Pawniards. The Grunt in the top-left corner has a level 46 Scraggy and a level 46 Liepard.
Go to the middle-right room and use the top-left transporter, then step on the red switch and go back. The Grunt in the top-left of the middle-right room uses a level 47 Weezing, while the one in the middle uses a level 46 Krokorok and a level 46 Raticate.
Finally, go to the bottom-right room and use the bottom-right teleporter, then step on the red switch and go back. The Grunt in the bottom-right room has two level 45 Deinos and a level 45 Sneasel.
Now that the barriers are down, go back upstairs and go through the door across from the stairs that you just came from. Go to the north end of the room and step on the teleporter.
The layout of this area is slightly different in the two versions. Here is what you find if you're playing White 2.
There are six rooms in this area.
The middle-left and bottom-left doors go to the same big area. You have to battle the Grunt in the table area. She has three level 45 Pawniards. You get the Plasma Card when you defeat her. This is required for inputting the password, so make sure you fight her.
If you are not playing the Japanese version, the password will be one of the following:
- 1101, 2202, 3303, 4404, 5505, 6606, 7707, 8808, or 9909
In the big room where you got the Plasma Card (explained above) the Grunt to the south has a level 47 Garbodor and will tell you a password hint when you defeat him.
In the same big room, talk to the Grunt in the top-left to have Reshiram and Zekrom added to your pokédex.
Also in the big room, there is an Electrizer that you can pick up.
Now you can leave the big room.
In the top-left room, the Grunt has a level 47 Weezing. When you defeat him, he tells you part of the password.
The Grunt in the top-right room has a level 47 Drapion and tells you a password hint when you defeat her.
The middle-right room has some Grunts who won't fight you. They tell you to use a bed to heal up, so do that if you want.
In the bottom-right room, the first Grunt has a level 46 Whirlipede and level 46 Watchog, and the second has a level 46 Krokorok and a level 46 Raticate. Both may give you a password hint.
If you didn't get the Plasma Card, go to the middle-left room and battle the Grunt in the table area to get it.
Hopefully you know what the password is now (see the list of passwords above). Go upstairs and go to the north end of the ship, then go in the door to return to the room with the barrier. Use the Plasma Card to input the password.
Frigate Cage (Both Versions)
Now you reach a room where you find Zinzolin and a Grunt. Walk up to Zinzolin. He'll show you the awful truth: they captured Kyurem and imprisoned it on the Plasma Frigate! This is that "new technology" that Zinzolin was referring to when he explained how they made unbreakable ice in Opelucid City.
Hugh will appear and you will fight Zinzolin and the Grunt together! Zinzolin sends out a Cryogonal, and the Grunt sends out a level 45 Liepard. After that, Zinzolin has a level 48 Cryogonal and a level 50 Weavile. The Grunt follows up with a level 45 Scolipede and a level 45 Watchog. Hugh has his starter and a Simisear.
When the battle is over, Zinzolin will taunt Hugh about his concerns for his sister's Purrloin. He'll say that since Kyurem is fully recovered, they'll use the DNA Splicers on it soon. Then the Shadow Triad will take you off of the ship. The Frigate flies into the air and sails away.
You and Hugh are left on the beach near Seaside Cave. Cheren arrives and says he thinks that the Frigate went to Giant Chasm. Go to Humilau City, then Route 22, and go to the northwest corner to reach the cave entrance to Giant Chasm.