After her shower, Luna had tossed and turned, still too wound up to sleep. It took a while, but her brain slid into a nice slice of REM cycle that ended abruptly three hours later when she sneezed herself awake.

A green envelope had been placed next to her pillow. Someone had entered her room without her knowing to place it there. She’d slept right through the intrusion. And all the fear she felt drained away the second she’d opened her present.

A small book as long as her hand, from wrist to fingers, was inside. A crescent moon encased in a shimmering atom had been stamped on the front cover, and the back had a riddle:

Your gift, a hidden world for the silent girl

A foolproof codex to find every door

Passages in the walls & under the floors

No need to wait for the trick to unfurl

With the Invisible Words of the Silent Girl

A lock with a diamond-shaped keyhole had kept her from opening it to read the pages. They’d almost been late for breakfast because they’d spent the morning searching for the key. Alex had the bright idea that “invisible words” meant invisible ink. They found a kitchen and tried to heat up the codex—in the oven at 314 degrees like the nonsensical recipe said—to see if maybe Jewel had used lemon juice to hide the location of the key. No dice.

At breakfast, when Luna had unrolled her napkin, she thought of unfurl—maybe the key was hidden in her room, wrapped in something. They unrolled all the perfectly folded towels in both their bathrooms. Tore through the guest socks in their closets. Checked inside the pillowcases, under their beds and flat sheets, behind the curtains, and nothing.

Nothing.

“Maybe there’s another hint in the recipe?” Luna pulled it up on her tablet. “‘Mix all colors.’ That’s us. We all have different color rooms, and we’re supposed to work together.”

Alex said, “It says ‘all,’ though. Maybe we should have asked the others for help.”

“I really don’t like that,” Luna complained. “If only two can win, we should only work in pairs.”

“Aye, aye, Captain,” he said, falling backward on the bed. “How about a nap? Nap sounds good.”

She lay next to him, staring at the canopy above her bed. “I think Stella wants to work with Nicole.”

“Mmhmm.”

“But I also think Jewel wants Stella to work with Harlow.”

“Mm.”

“Because they’re the remainder. Francis pretty much stared at Nicole the whole time at breakfast. I think he’s here for her. Which is extremely suspicious.”

“That’s some hardcore deducing.”

“I mean, I don’t have any proof, but I have a feeling,” she said. “And, you know, their rooms are next to each other, so that makes it kind of obvious too.”

“How are you not tired?” he asked, amused.