I opened my eyes, and blinked. For a minute, I couldn’t remember where I was. Then, through the darkness I saw the shadows of the mummy cases all lined up on the platform. I wasn’t scared, though. I mean, I have to look at Molly-the-Monster’s ugly face every morning. So why should I be scared of a load of old mummies?

I didn’t know how long I’d been asleep, but Lyndz hadn’t woken us up yet, so it couldn’t have been very long. I looked round at the others. They were all asleep, curled up in their sleeping bags. We were all lying in a row next to the platform which had the mummy cases on. Guess who was the furthest away? Yeah, go to the top of the class. Flissy Baby wasn’t taking any chances, just in case one of the mummies fancied a midnight feast.

I raised myself on my elbow, and looked cautiously across the room. Frankie’s mum was over the other side of the platform, and it looked like she was fast asleep, too. She’d been a bit surprised last night that we were so keen to go to bed, and that we didn’t want to stay awake for ages chatting, like everyone else was doing. Still, I don’t think she suspected anything was going on!

The museum was dead quiet now, though. Everyone had to be asleep, even Ryan Scott’s group, who were in the Roman Room next door. They’d kept trying to frighten us after lights out by tapping on the wall. Boys. They’re s-o-o-o-o pathetic.

I rolled over, and picked up my watch, and my eyes nearly popped right out of my head. Half past four!!! What had happened to Lyndz’s ‘brilliant’ system to wake everybody up? I leaned over and shook Frankie, who was lying next to me. When she opened her eyes, I waved my watch in front of her face.

“It’s half-past four!” I mouthed silently, pointing at the door.

Frankie nodded, and shook Rosie, who was next to her. Rosie woke Lyndz up, and Lyndz sat up, yawning and looking puzzled.

“It’s not two o’clock, is it?” she whispered.

“No, it’s half-past four!” I whispered back. “Great waking-up system, Lyndz!”

“We’d better go,” Frankie said, sliding out of her sleeping bag. “It’ll be getting light soon.”

Lyndz rolled over, and poked Fliss. Fliss opened her eyes, took one look at the mummy cases, and let out a little scream. Lyndz lunged across and tried to stop her, but it was too late.

We all froze, waiting for Frankie’s mum to sit up and ask us what was going on. But she didn’t. We heard her roll over in her sleeping bag, and then there was silence.

We didn’t even dare sigh with relief. Instead we just got to our feet, and tiptoed over to the door, which was so heavy, Frankie and I had to hold it open to let everyone slip silently out. When we were all safely outside in the corridor, we sighed with relief.

“Sorry,” Fliss said shakily. “The mummies nearly scared me to death.”

“From now on, we’ve got to be really quiet,” I whispered. “If anyone wakes up, we’re dead.”

We had to get the mask first, so we tiptoed down the dimly-lit corridor to the activities room, hardly daring to breathe. We had to go past the Roman Room, where Ryan Scott’s group were sleeping, and past the Art Gallery, where Alana Banana’s group were with Miss Hill. Luckily, the doors were closed.

The activities room was really dark, but we didn’t dare put the light on. The others waited by the door, while I groped my way round the tables, trying to find our mask. Frankie was holding the door open, so there was a bit of light from the corridor, but not much.

“Hurry up, Kenny,” Fliss was moaning, “if we get caught, Mrs Weaver’ll never let us go on another school trip ever again.”

“Oh, great big fat hairy deal,” I muttered. I was feeling my way round the tables, and knocking things over, including a pot of glue. “Oh, rats! Now I’ve got glue all over my hand!”

“Never mind that,” said Frankie. “Just get a move on!”

I found the mask, and hurried back over to the door. “Got it!” I said triumphantly.

Fliss took one look at the mask, and stepped behind Frankie.

“Keep that thing away from me, Kenny!” she hissed, giving me a dirty look.

“It’s that scary, huh?” I slipped the mask over my head. “Let’s see what it looks like when it’s on.”

Lyndz had neatly cut out the big eyes, so that I could see through them. The others looked impressed (except Fliss, of course).

“It’s brilliant!” said Frankie. “The M&Ms are going to wet themselves!”

“Serves them right!” said Rosie.

I took the mask off again, and put it under my arm.

“Come on, then. What’s the quickest way to the Doll Gallery?”

“We can take a short cut through the Costume Rooms,” said Fliss.

So we tiptoed along the corridor to the Costume Rooms. We got lost a few times, because there were so many twists and turns, but eventually we made it. Frankie pushed the door open a little way, and then froze.

“What’s biting you?” I began.

“SSHHH!” Frankie hissed. “There’s someone in there!”

“It’s a ghost!” moaned Fliss, clutching Lyndz’s arm.

“Ow!” said Lyndz. “Let go, you’re hurting me!”

“QUIET!” ordered Frankie, in a whisper that was louder than anyone. She let the door swing softly back into place. “Caroline Powell’s group’s in there, with her mum. We’ll have to go a different way.”

I thought for a minute. It was lucky we’d been to the museum so many times before, and knew our way around.

“We’ll have to double back, and cut through that room that’s got all the statues in it. Come on.”

We hurried back down the corridor, and after a few false starts, we made it to the right room. Frankie pulled the door open just a bit, and checked that none of our class were sleeping inside, then we all went in. It was a big room, with a large window in the ceiling, and a light had been left on, although it wasn’t very bright. There were white stone statues of people and animals all round the room. Some were just heads, but others were really big, reaching almost to the ceiling.

“I don’t like this,” said Fliss nervously, as we walked through the room towards the door on the opposite side. “They’re all staring at me.”

“They’re statues, dummy,” I said. “They’re not real.”

“They might be,” said Fliss. “They might come to life at night.”

“Oh, grow up, Flissy,” I said impatiently “Anway, even if they did, what do you think they’re going to do?”

“They’d probably go and find some clothes,” said Rosie, with a grin. “They look pretty cold.”

That made Fliss giggle. “They could definitely do with some underwear,” she said, and the others started to giggle too.

“Oh, grow up and shut up!” I sighed, reaching for the door. “Everyone ready?”

Fliss was still giggling, so I gave her the evil eye until she stopped. Then we slipped out into the corridor.

“Which way do we go now?” Rosie asked.

“That way,” said Frankie, pointing right.

“That way,” said Fliss at exactly the same moment, pointing left.

We went right, because Frankie usually knows best. But we had to go quite a long way down the corridor before we got to the Doll Gallery.

“This is it!” I said quietly, as we stopped in front of the doors. My heart was pounding with excitement. I’d waited a long time to get my revenge on the M&Ms, and now I was going to enjoy it. “I’m going to take a look inside, and find out where the M&Ms are.”

“Be careful,” said Frankie.

I laid the mask carefully on the floor, and put my face to the glass at the top of the door. I could just about see in. The room was quite dark, but someone had left their torch on, so I got a pretty good view. The dolls were in glass cases all around the walls, and there were six sleeping bags dotted in different places around the room. The M&Ms were in the perfect place, not far from the door where I was looking in. Best of all, Mrs Weaver was right over the other side of the room.

“Ace!” I whispered to the others. “The M&Ms are right here, and Mrs Weaver’s miles away!”

“I want to see!” said Fliss.

“Me too,” said Rosie. “I want to watch the M&Ms faces when they see Kenny in the mask!”

I shook my head. “No way,” I said. “They’ll see you for sure.”

“Hang on a minute,” said Frankie. “We could go round the side, and look through the curtains.”

There was a long row of windows at the side of the gallery, where the curtains had been drawn, but they didn’t quite meet.

“Go on, then,” I hissed. “But make sure you don’t get spotted.”

It was all right for me, I had the mask to hide behind, but I didn’t want the others to get caught.

I waited till the others were in position at the side windows, and Frankie gave me a thumbs-up. Then I picked up the mask, and slid it over my head. I got it into position so that I could see through the cut-out eyes, and then I peered through the window at the top of the door. The M&Ms were only a few yards away. In fact, they were so close that I could hear Emma Hughes snoring.

I took a deep breath, and tapped on the glass!