There's three of them?

Showdown in Space

Sonic was at the ARK Colony sitting inside a shuttle, speaking to Topaz over radio.

"Topaz, I'm transmitting my report now. Over." Sonic said on the radio.

"Be careful, Sonic. That space colony is a dangerous place." Topaz said over the radio feeling the ground shake as the ARK descended."

At the Eclipse Cannon Shadow and Silver were still fighting creating a hole in the wall, revealing a Power Ring.

"You've interfered for the last time!" Silver said and threw more Chaos Spears at Shadow, who leapt up and grabbed the ring.

He used a ring-powered home attack on Silver, knocking him to the ground.

"All right, Silver. What's goin' on here?" Shadow said as Silver sat up.

"You'll find out." Silver said then they felt the room shake. "Shadow, your time is running out!" he said and flew through the hole in the hall.

"Wait!" Shadow said and turned around to see a timer that read 00:23:45:00.

Meanwhile Chris, Tanaka, Knuckles, Amy, and Tails entered the computer room. Eggman slammed his fist on the console.

"He tricked me! My own grandfather tricked me!" Eggman said.

Suddenly a door sealed away the Chaos Emeralds.

"The Chaos Emeralds!" Knuckles said and Gerald's message played on the big screen.

"The countdown marking my final revenge on this world has begun! In just a few minutes, you will be destroyed. Soon, Space Colony ARK will hurtle through the atmosphere and crash into this planet with devastating force!" Gerald said.

Only twenty minutes remained. Everyone around the world saw Gerald's message.

"You have no time to prevent this disaster, and absolutely no hope of survival. Your ruler took my granddaughter Maria from me, so I'm destroying everything you care about. Now you'll feel what I felt when I lost Maria. You will see. You will see. You'll see!" he continued.

"Who is that guy? And what does he mean?" Amy asked.

"That is Professor Gerald Robotnik, He was a scientific genius and my grandfather." Eggman said and Gerald's message repeated.

"The countdown marking my final revenge on this world has begun!" Gerald said and the space colony shook again.

"Hey, it feels like this place is breaking apart!" Knuckles said.

"Soon it's going to get a lot worse." someone said and Knuckles turned to see Sonic approaching. "I've just checked the colony's propulsion systems. The computers are locked, so we can't reverse course. Looks like there's nothing we can do."

"Grandpa, destroying a planet is one thing, but destroying your grandson is another." Eggman said as Shadow stood at the entrance of the room.

"What's going on here?!" Shadow asked.

"Shadow!" Chris said.

"If you came here for a showdown, Shadow, forget it. Soon we'll all be vaporized." Eggman said and Shadow joined the others.

"Come on. Don't be such a quitter, Eggman. Maybe if we work together, we can get out of this mess." Shadow said.

As he looked at Gerald's message, Eggman typed on a computer.

"When I hacked into the database on Prison Island, I found my grandfather's diary." Eggman said and handed the computer to Shadow, and Chris looked over his shoulder and read along.