Zac rolled onto his side and tried to fell for whatever it was. When he couldn't find it, he rolled onto his back again, only to feel this thing sticking into his butt again.
This made him draw the conclusion that he must have something in his pocket. He rolled onto his side, yet again, and reached into his back pocket.
"Oh my goodlyness!" Ripples gasped. "Are you a pickypocket?"
"Pickpocket?" Zac repeated. "This is Taylor's rock. I found it lying about the house a few days ago. I keep forgetting to give it back to him."
"But, but, but Frog-head has a rocky just like dat! She has it with her all da time."
"Really? That's interesting." Zac yawned.
He put the rock on the bedside table and went back to sleep.
**********
In the morning, Zac picked up the rock as he walked over to the food. Using his Restoration, he made certain that if the food had been in anyway tampered with, it wasn't any more. Then he ate.
"So, Mr Rock, the frog has one just like you." He said, sitting down and holding up the rock. "I find that very hard to believe. You are the strangest rock I've ever seen."
Zac held the rock closer, and for the first time took a good look at it.
"Although, I suppose, you do feel slightly different from other rocks."
It was then that Ripples flew over, and Zac realised the truth.
"Oh my gosh!"
"What? What?" Ripples asked.
"I know how I knew you had Telepathy!"
"Ooh! How?"
"This rock. It has to be this rock. It's got to be some kind of device. Taylor can move his mind into it from his body, you see, he has Deep Telepathy."
"What's Deep Telepathy?"
"Oh, he had create these probes and pick people's brains and do them damage and read people's thoughts and stuff."
"Oh." Ripples paused. "Is there Shallow Telepathy?"
"Well, I don't know. Maybe there is, maybe there isn't. My point is, if this rock is how I knew you had Telepathy, and Gretel has one, then that's probably how she knows when there's a telepath nearby."
"Ooh. Zacky is smart."
"It might shield as well... and if she know I have it, it could explain why she calls me a telepath when I'm not." Zac grinned up at Ripples. "If that's the case Ripples, you hang around this rock when Gretel appears. This is probably why she hasn't realised you were here."