No time to think. We run from the mob of zombies, tear along the corridor, knowing we don't have much time.

As we pass an open door to a classroom, Linzer ducks inside. "I'm hiding!" she screams, slamming the door shut on the rest of us.

Meths starts to slow but Stagger Lee bellows at him, "Leave her!"

We press on. My heart's hammering. I'm finding it hard to breathe. I was never the fittest - too many helpings of fries and not enough exercise. I start to drift towards the rear of the group. We turn a corner, then another. I've lost track of where we are. The zombies are drawing closer. The mutants in hoodies must be with them because I hear an occasional whistle.

I'm rushing past a window when I catch a glimpse of open space. I stop and yell to the others, "We're next to a courtyard. I'm jumping."

"We don't know what's down there," Trev roars. "It could be full of zombies."

I grin ghoulishly. "Only one way to find out." I back up from the window, then hurl myself at the glass, covering my face with my arms. There's a good chance I'll slice open a vein or artery, but I'd rather bleed to death than be devoured by the living dead.

I smash through the window and whoop insanely, half-terrified, half-buzzing. My arms snap open and flap wildly. A brief glimpse of the ground coming fast towards me. Then I land in an untidy heap and roll awkwardly. The air's knocked out of me. Shards of glass nick my hands and knees. But I'm alive. I'm not badly injured. And the courtyard's empty.

"Come on!" I shout at the others.

Seez follows first, bursting through another pane of glass. There's a wide hole now and the rest can jump cleanly. They pile after us, landing hard, picking themselves up, a few cuts and bruises but no broken ankles or severed arteries.

Suze and Ballydefeck are last. Suze stares at the drop with terror. She's crying.

"Hurry up," Ballydefeck says, grabbing her.

She shakes him off. "I can't. I'm afraid of heights."

"It's not that bloody high!"

"I - "

A scream from a window on the other side of the courtyard stops her. We all look. Linzer is pressed against the glass, her face contorted. Zombies are bunched around her. They yank her out of sight. Looks like Cass might have been right about them having a keen nose for the living.

"Get down and drop, then," Ballydefeck barks, getting to his knees and backing out, holding on to the sill.

"All right," Suze moans, shutting her eyes. "But I can't look. You tell me where I have to - "

There's a blur of motion. A zombie tackles Suze and she's gone before she can scream. Ballydefeck yelps and lets go. But hands snake out and grab his arms. He's hauled back into the room, roaring and cursing.

Several zombies lean out through the shattered windows, and I'm sure they're going to jump in and finish us off. But the sunlight unnerves them. They wince, cover their eyes and back away into the gloom. Before hungrier or braver zombies can take their place, we find the nearest door and race back inside, stumbling slightly, feet stinging from the jump, but delighted to be alive, all too aware that we could have very easily gone the same way as Linzer, Suze and Ballydefeck.