They went back to the hideout, where Frina paced.

"We need a plan to beat Thad," she said, tapping her chin.

"Who's Thad?" Eli asked.

"Thad is Dr. Blakk's nickname," Frina explained.

"How do you know his nickname?" Trixie asked.

"Because I know him."

"How do you know him?" Trixie asked suspiciously.

"Because… Thad used to be my friend." Everyone gaped at her.

"But he's not your friend now, right?" Eli assured.

"How could I be friends with HIM anymore?" Frina exclaimed. "That lying, selfish, cheat!"

"So, how is it you were friends?" Eli asked.

"Because," Frina explained. "Thad-or Blakk- is a Denekk. I know all the Denekks."

"Wait, Black is a Denekk?" Trixie exclaimed.

"Yeah," Frina said. "His jewel is in a ring."

"So, your jewel gives you the ability to shape shift, what can Blakk do?" Eli asked.

"He can move stuff with his mind."

"Why doesn't he?"

"I don't know."

"So," Eli said. "Are Denekks good guys, bad guys, or neither?"

"Good guys. We protect people. We can all speak to Shadow Clan, because the Shadow Clan gave us our jewels. Shadow Clan had the secret to Ghoul slugs. Blakk found out about it and demanded they tell him. When they refused, he recruited others, some by force, some by trickery, and some volunteered. They fought the Shadow Clan, and in the end, the Shadow Clan was forced to retreat."

"So that's how Blakk found out about Dark Water," Kord said. Frina nodded.

"Um, how old are you?" Pronto asked.

"Twelve years old," Frina said.

"You seriously just fought Blakk that young?" Kord exclaimed.

"Yeah," Frina said. "I'm the youngest Denekk."

"Where are your parents?" Kord asked.

"I don't have any. The other Denekks were my family after my old family died in a fire, and then when Blakk fought the Shadow Clan, the Denekks had been scattered throughout Slugterra." Just then, Burpy and all the other slugs fell asleep and started snoring loudly.

"What's going on?" Eli asked. Frina smelled something strange. As the smell became more distinct, she realized it was bad. She spun around towards the door and hissed. Then she turned to a wolf and stalked close to the door.

"Frina?" Trixie asked. The door swung open, and there stood Dr. Blakk, wearing a ring with a black gem.