They all froze on the stairs.

“Who’s that?” Marly asked, gripping the banister.

Whoever it was rang the doorbell again. Then pounded on the door.

“Should we answer it?” Sai asked.

“Let’s see who it is first,” Isla said.

They crept back down the stairs and over to the front door. Marly put her uncovered eye to the peephole.

An angry green eye stared back at her.

Marly gasped. “It’s Jay Summerling!”

“I know you kids are in there,” Jay growled. “Open this door!” He pounded on it again.

Marly shrank back. Her heart was pounding almost as hard as Jay’s fist. “He must not know the code for the lock,” she said.

“Good. Let’s not open the door,” Isla said firmly.

Marly was in total agreement there.

“I’ll go make sure the back door is locked,” Sai said. “We don’t want him to sneak in or anything.” He zoomed down the hall.

“You kids are trespassing!” Jay yelled. “Open this door right now or I’ll call the police!”

“Go ahead!” Marly couldn’t resist yelling back. “We’re not trespassing. We’re allowed to be here. Are you?”

“Shh!” Isla hissed, grabbing Marly’s arm. “Don’t talk to him!” Her eyes were wild with fear.

“He already knows we’re in here,” Marly said. He may have even followed them from Ms. Lovelace’s office. Maybe that was why she’d had that creepy feeling that someone was watching them before. Maybe Jay had been watching them.

Strangely enough, Marly didn’t feel scared. Not too scared, anyway. Not as scared as Isla seemed to be. Maybe that was because she knew her mom was right next door.

“Anything you find in that house is mine, not yours! Do you hear me?” Jay yelled as he pounded some more.

Marly and Isla eyed each other. What does he think we are going to find in this house?

Finally, the pounding stopped. Footsteps thudded across the front porch and a shadow passed by the living room window.

“Uh-oh. What if he’s going around to the back door?” Marly whispered. She and Isla hadn’t moved.

“Hopefully Sai got it locked,” Isla whispered back.

But Sai hadn’t come back yet.

“Sai?” Marly called in as loud of a voice as she dared. “Where are you? Is the back door locked?”

No response.

“He maybe can’t hear us,” Isla said.

Marly and Isla inched along the hallway toward the kitchen. The back door rattled. Then someone pounded on it.

Marly froze. She grabbed Isla’s hand. Her heart pulsed in her throat.

But no one came in.

Finally, the pounding stopped and the house went silent.

“Is he gone?” Isla mouthed.

“I don’t know,” Marly mouthed back. They continued down the hall, their backs pressed against the wall. But when they got to the kitchen, Sai wasn’t there.

“Where is he?” Isla said, barely above a whisper.

Marly let go of Isla’s hand and took slow, careful steps toward the back door. She pressed her ear to the door. Then, with a shaky finger, she moved the shade just enough to see out onto the back porch and yard.

No one was out there.

“I think Jay’s gone,” Marly said with relief. “But yeah, where’s Sai?”

Marly and Isla grabbed hands again and moved into the dining room. No Sai. Then the living room. Still no Sai.

“Why can’t he just stay in one place!” Marly grumbled.

“Because he’s Sai,” Isla said.

Marly nodded. That was exactly why.

Then Marly noticed the electric fireplace. Strange. The logs were all lit up!

“Isla?” Marly said, staring at the fireplace. “Was the fireplace on when we were in here before?”

Isla turned. She grabbed her hair in her fist. “No,” she said, shaking her head. “Who turned it on?”

“Sai?” Marly suggested. She hoped it was Sai. Because if it wasn’t him, who else could it have been?

She walked along the fireplace and examined every single brick. “Aha!” she said when she noticed a small switch sticking out between two of the bricks. “I bet this turns it on and off.” She flipped the switch and the fireplace went off.

That made her feel better.

But thirty seconds later, the fireplace came on again.

All by itself.