“WE NEED A headquarters for our investigation.” Emma paused to think for a second. “I know just the place.” She darted off again, expecting the other two to follow.

The three kids went up the stairs, and then down the hall. They passed the room JJ and his mom were sharing on the way, and JJ wondered if she was in there. Was his mom involved in this murder—or worse: was she the murderer? It had to be a giant mistake.

“Do you think maybe Mr. Clark is wrong about Mr. Barclay’s death being a murder?” he asked Penny. Emma was now up ahead, impatiently waiting for the two of them to catch up.

“Why would he lie?” Penny asked.

JJ didn’t know how to answer that question. He just didn’t want his mom to be a suspect.

Penny added, “It does seem like we’re missing something, though. Like an important clue.”

“We should figure out what clues there are,” JJ said. He was eager to solve the mystery of Mr. Barclay’s murder, to clear his mom’s name, and to get to ghost hunting—that was the whole reason he was here, after all. He looked around, hoping to catch a ghost.

The lights flickered. “Dude,” JJ whispered.

Before Penny could say anything else, the two kids heard Emma’s voice from down the hall.

“This way!” she called.

Ghost hunting would have to wait. JJ sighed and joined Penny and Emma.

Emma opened a door, which led into what looked like another hotel room, only it wasn’t. It was a small space, almost like a dressing room, with two giant wardrobes and a mirror. Emma grinned as she opened one of the wardrobes. “When I was little, I’d pretend I was going to Narnia. You know, like the book?”

The Lion, the Witch and the Wardrobe was on the Battle of the Books list, but JJ didn’t want to admit that he’d never read the whole thing. He did, however, know she was talking about the wardrobe being a portal into a different world.

“I loved that book,” Penny said.

JJ wondered if he was missing out, not reading. But it took him forever just to read the first few chapters.

Emma pushed the clothes aside and opened a small door. It led to another narrow hall, only the walls were bare this time. The hall seemed to climb like a ramp before they reached another door. Emma opened the door, and they arrived in another sitting room.

Penny sat in one of the oversize chairs. It looked like it was going to swallow her whole, it was so giant.

Emma sat in another chair. “This room is right over the kitchen,” she said. “Sometimes, I can hear dishes and silverware clanking as they hit the counter, and smell what my uncle is cooking up for Mr. Barclay.” She blinked as if she was holding back emotions.

“You must miss Mr. Barclay,” Penny said.

Emma nodded, looking sad.

JJ scanned the room. The part of him that wanted to ghost hunt started wondering if it was haunted. While Emma was talking to Penny, he rummaged through his backpack and pulled out his EMF detector.

“What’s that?” Emma stepped in front of him. JJ jumped at the sound of Emma’s voice. He hated it when people snuck up on him.

Before he could manage to get too irritated, JJ’s attention was diverted to the EMF detector and its sudden continuous beeping. The detector was about the size of a cell phone, with a small screen and lights that arced around the bottom of the device. It was going crazy!

“It’s an electromagnetic field detector—EMF. It shows you anything with an electromagnetic field, like wiring in an old house, or ghosts. And look!” He showed both Penny and Emma how the lights on the detector showed there was electromagnetic activity. Right over by the wall in front of them, sort of.

“Maybe this room is haunted,” Emma said.

“Because that detector thing is bleeping?” Penny asked with a raised eyebrow.

“It’s science, you know,” JJ muttered.

“We need to focus on the murder investigation first,” Penny said. “No ghost hunting.”

Emma smiled. “So let’s figure out who killed Mr. Barclay.”

JJ put the EMF detector away and pulled out his logbook and pen; he looked at the crisp white paper. “I don’t know about you guys, but I have no idea how to catch a murderer.”

“Let’s read more of The History of the Barclay Hotel,” Penny suggested. “There might be more in there about Mr. Barclay, and motives to kill him and stuff.”

“No,” JJ said quickly. He was beginning to really hate that book.

“Fine. How about we use the game?” Penny suggested. She pointed to a box in the corner of the room.

“Mr. Barclay’s Catch a Criminal?” JJ thought about that for a second. “Isn’t that just made up?”

“But it’s Mr. Barclay’s game.” Penny motioned around the room. “He set this whole thing up, and brought all the guests here to try to catch a murderer.”

JJ said, “Okay, let’s use the game, then.” He blew off some dust and opened the box. It sounded like it was exhaling. “It looks brand-new!”

“Mr. Barclay produced five thousand copies but sold very few. He has a whole bunch in storage somewhere,” Emma said.

JJ put the box lid aside and pulled out the game pieces.

There was a board, character cards, and clue cards.

“It looks an awful lot like that Clue game,” Penny said.

“I’ve played this game once before,” Emma said. She spread the game components out on the dusty wood floor. “It’s more like a murder mystery game. You have to take on parts as players, see? You’re each acting out a part.”

There were disguises in the box: a mustache, silly glasses, a necktie. JJ thought about all those masks in the den, and Mr. Barclay’s love for the theater, and suddenly this game made total sense.

Emma continued, “Everyone has to play a part, and one of you is the killer. You’re supposed to question each other to figure out who the murderer is.”

Penny thought about the time that her parents hosted a murder mystery game at their house. She had so much fun, and this board game sounded the same.

JJ put on the silly glasses. “Honestly, I don’t see how this helps us find Mr. Barclay’s killer.”

Penny pulled out a notepad. “We create character sheets, like these. Then we add clues—secrets we find out about the others—which will tell us whodunit.”

“Who-whatsit?” JJ asked.

“Whodunit,” Emma said, like JJ should know. “That’s the killer, but you also call a mystery story that: a whodunit.”

“All my favorite Agatha Christie novels are whodunits,” Penny added. All serious mystery readers who practically live at the library, like Penny, know Agatha Christie.

JJ took off the silly glasses and put them back in the box.

Penny put the game’s notepad back too. “I know what we need to do.”

Emma and JJ looked at her.

Penny said, “My grandpa is—was—a detective, so I learned a few things from him. We need to interview our suspects, and find out three things.”

Her two new friends looked at her in suspense.

“We need to find out who had motive, means, and opportunity.”