JJ PUT HIS key in the lock and entered his hotel room. He thought about what motive his mom might have to kill Mr. Barclay. Certainly, she didn’t have any motive, JJ thought. She made PB&Js for a living, for goodness’ sake! Murderers weren’t sandwich artists, right?

JJ wanted to ask her, but his mom wasn’t in their room. And it wasn’t like he could send her a text, given that there was no cell phone reception and all. Anyway, what would he say? “Hey, Mom, did you kill Mr. Barclay?” Investigating your own mom for murder was complicated.

There were three sticky notes on the mirror, written in his mom’s handwriting:

MOM

JAM

BATH

For most people, these three notes wouldn’t mean anything. But JJ and his mom had their own language. Those three sticky notes were the clues JJ needed to find his mom.

Mrs. Jacobson’s suitcase was open on the big bed, and her clothes had been moved around. Like she’d been searching for something.

Still, JJ didn’t get it. The bathroom door was open, so she wasn’t in the bathtub. He stopped to think for another moment.

Mom, jam, bath . . . Jam could be like jamming, as in music, but that made no sense . . . Maybe his mom was in a jam. Like being a murder suspect!

BATH wasn’t an actual bath.

Those three words were part of his sight word list—somewhere in third grade, JJ thought.

His mom was in the hot tub. Hot tubs are like catnip to adults, JJ knew. Especially adults who were stressed out, like his mom. Adults who were in a JAM.

He smiled, folded the sticky notes, and put them in his backpack. Of course, JJ was a smidge optimistic in his belief in his mom’s innocence. Mr. Barclay clearly thought she was a suspect. That was why JJ’s mom had been invited, just like the other suspects.

But JJ was biased. This was his mom, after all. She helped him with his homework, and often brought new PB&JJ sandwiches for him to try. She was nice to his friends, and always let anyone stay for dinner (even when it was the whole Book Club). A mom like that couldn’t be a murderer.

JJ closed the door to their room and then locked up. He walked down the hall and stopped right past room 217.

What if he could get some ghost hunting in? Maybe just a little bit? He had that bet with Penny, and his plan was to do as much ghost hunting as possible—and what better place to start than the most haunted room in the hotel, right? Maybe Detective Walker would let him in.

JJ knocked, and waited. He even tried to use his key to pick the lock on the door, but it didn’t work. Bummer. Maybe he could get Penny to let him in later, but then he’d have to listen to her try to disprove the existence of ghosts.

JJ decided this last option might be his only one. And Penny was a really good investigator—that could come in handy when ghost hunting.

When he got to the other end of the hall, he hit the call button for the elevator. He waited a full minute before the doors opened. Once he had gotten in, just as the doors began to close, a hand stuck inside.

“Hold up!” Penny called. She got on the elevator and gave JJ a quick smile.

“Where are you going?” JJ asked her as the doors closed.

“I’m looking for Ms. Chelsea. I think she might be bowling,” Penny said.

JJ said, “I’m trying to find my mom. She’s in the hot tub.”

He pressed the button for the basement, knowing that was where the bowling alley was too. The elevator buttons were antique looking, faded with copper trim and dim light inside. There were mirrors lining the elevator walls.

Strange retro disco music was playing in the elevator, probably Mr. Barclay’s favorite.

When the elevator was almost at the basement level, there was a giant CLANK! sound. The elevator and the disco music stopped. The lights flickered, then went off.

Penny made a squeaking noise, like a mouse. JJ sucked in his breath.

The elevator went pitch-dark.