After the Championship match, Geeta and Rika ask you to accompany Ms. Briar on an expedition.

Go to Zero Lab

When you arrive in Area Zero, Ms. Briar says that you must go to the deepest part of the area. After the cutscene, go into the building behind you. To the right of the door, there is a glowing green spot. Stand on it and choose Research Station No. 4. From there, go outside and glide down to the lowest part of the area. Go around the largest building until you see its entrance. Approach the entrance and there will be a cutscene.

Afterward, go up to the panel and check on it. Say Yes when asked to open the gate. After the cutscene, go through the gate that opened. In the tunnel, go straight ahead until you reach the end, then go through the opening on the right. Go counterclockwise around the room, and there will be a cutscene.

After that, go up to the elevator door and it will automatically open. There will be another cutscene.

The Underdepths

The elevator takes you to the Underdepths of Area Zero. After the cutscene, go forward and walk across the stone bridge. Approach the crystal formation on the other side, and there will be another cutscene.

After the cutscene, you need to battle a level 78 Glimmora that has Tera type Stellar. Because of the Stellar Tera type, the pokémon gets a one-time strength bonus per move type. For example, the first time it uses a Poison-type attack, the attack will stronger, but if it uses Poison-type attacks again, they won't get a boost. Glimmora has the ability Toxic Debris. It knows the moves Sludge Wave and Power Gem. It can't be caught, so just focus on defeating it.

After the battle, you get Stellar Tera Shards. Go through the tunnel that opened. You will begin to encounter wild Pokémon. Be sure to pick up the item along the way to get more Stellar Tera Shards.

As you go farther, you will see a TM to the right. You can go up the angled piece of rock and jump from there to reach it. It is Hydro Pump.

Back on the main path, pick up the Full Restores that are sitting on top of a small hill of rock.

Farther ahead, you find the others looking at another crystal barrier. If you talk to them, they mention that you will need to defeat another sparkling pokémon. Jump onto the nearby crystal and pick up the Ice Tera Shards there, then jump across to where you can see some long crystals leading up to a TM (Flare Blitz), an item (Flying Tera Shards), and a Terastal Noivern. Approach the Noivern to start the battle. It is level 78 and has Tera type Stellar. It knows the move Boomburst.

Afterward, the crystal barrier disappears, and you get more Stellar Tera Shards. Glide down to where the barrier was, and approach the others. There will be a cutscene.

Go through the new tunnel and you will find the others looking at another crystal barrier. Look to the left of the barrier to find a tunnel. Go through to reach a large room. Up ahead, you can see a Terastal pokémon. To the left of where you emerged from the tunnel, there is a Max Revive, and farther than that, there are Grass Tera Shards on a large crystal. Climb to the top of that crystal to find the TM Outrage.

Turn around and you can see an item on a stone pillar straight ahead. Go there to get Ground Tera Shards. Farther ahead, you can glide to the top of another stone pillar to get Psychic Tera Shards.

Farther ahead, there is a ledge on the right side of the cliff. Land there and you will reach a cave. Inside the cave, there are some Dark Tera Shards. Make your way to the top of the center structure, and you will be able to see the Terastal pokémon. To the left, pick up the item to get some Normal Tera Shards. Then approach the Terastal pokémon. In Pokémon Violet, it is a level 79 Iron Thorns with Tera type Stellar. It knows Pin Missile.

After the battle, glide across the room and go back through the tunnel to where the others are waiting. There will be a cutscene.

Go through the tunnel, and look to the right to find some Max Potions. Then make your way down the spiral, picking up the items along the way (Full Restores, Max Elixirs, Full Heals, Max Revives, and Max Potions).

At the bottom of the spiral, find Carmine, who is looking down a tunnel full of water. Go through the tunnel and you will see a Terastal pokémon beneath a crystallized tree. Before you go to the pokémon, look for a long crystal to the left. The item on top of the crystal structure is Ghost Tera Shards.

Then approach the Terastal Garganacl. It is level 80 and has Tera type Stellar.

Afterward, go back through the tunnel and approach the others. Continue going through each tunnel and approaching the others, and watch the cutscenes.

Prepare for battle, and talk to Kieran and say Yes when you're ready.

Battle Terapagos, the Indigo Disk

Terapagos has the Indigo Shift ability, transforming into Terastal form. Terapagos's Tera Shell distorts type matchups, making moves not very effective against it. Terapagos knows Earth Power, Zen Headbutt, and Water Pulse.

Battle Terapagos, the Hidden Treasure of Area Zero

You and Carmine will battle Terapagos in a Tera Raid. Terapagos has Tera type Stellar. Carmine has a level 75 Sinistcha. Terapagos knows Tera Starstorm and Zen Headbutt. Before you can Terastallize your pokémon, you need to attack Terapagos a certain number of times. You can press the Terastallize button to find out how many more times you need to attack. Ms. Briar will also mention when you can Terastallize. Even if your pokémon faints, you will be able to Terastallize again after a certain number of attacks.

After you break Terapagos's first shield, it will absorb the Terastal energy of your Terastallized pokémon, removing the Terastal effect and putting up another barrier. Continue to attack until you can Terastallize again, then break down its barrier.

After you break the second barrier, Kieran will send out his level 82 Hydrapple. Once again, Terastallize when possible, and attack until Terapagos's barrier is destroyed. This time, Terapagos won't be able to absorb Terastal energy, so your pokémon will stay Terastallized.

When Terapagos is defeated, you can choose to catch it. You can use any type of pokéball. They are all guaranteed to catch it. Congratulations!

Post-Game

For a list of things to do after the end credits of The Indigo Disk, see Post-Game for The Indigo Disk.