He took a key from around his neck – it was silver with the end shaped into the symbol of the Guild. With a soft click, a hidden doorway in the wall paneling opened and there was a rush of air. The apprentices looked at each other in wonder.

“Exciting, isn’t it?” said Craftsman Primrose. He pulled three keys on chains from his bag and passed them one each.

They followed him down a dimly lit spiral staircase. The curved brick walls had chaos lamps set into recesses that gave off a warm glow. At the bottom, rather than finding themselves in a basement room, the space opened up and they found themselves on a platform in an underground tunnel. Around the height of two people, the tunnel’s arched brickwork was illuminated by many flickering chaos lamps, and it was warm and smelt earthy. Beside them, running the length of the tunnel, was a metal tube that half-filled the space.

“This is your daily transport – the pneumerator!” said Craftsman Primrose proudly. “Developed by the masters using the old Medlock sewage system.”

“Gross,” said Cora.

“No, perfectly spotless, and it’ll get us to the Guild in under a minute. Of course, you can walk above ground if you’d prefer, but that’d take you around an hour, and you’d have to pass through security at the outer gate,” said Craftsman Primrose. “There’s a pneumatic station at the other end of this tunnel, and it works to either push or pull us. It’s a wonderful invention.”

Prue marvelled at the sound of it, and instantly imagined one back home to get you from the far field back to the farmhouse.

“Now, if the pod is at this end, the lever on this control panel will be up; if it’s at the other it’ll be down.” He pulled the lever up. “It can get rather busy at peak times, which is why I’ve brought you along early.”

In hardly any time at all, there was a whooshing sound and the glass panel in the tube illuminated.

“It has a built-in braking system. It used to be manual, but it was … problematic. Come along, everyone!” Craftsman Primrose reached for a handle and slid open a door in the tube. One by one, they stepped inside the pod, which was just big enough to stand up in with dozens of red leather seats facing forward.

“You can sit with me, Agapantha,” said Cora, grabbing her arm.

Prue didn’t mind sitting with Craftsman Primrose; at least she would be able to ask him questions.

“This silver lever is to close the pod. Then, in about five seconds, we’re off.”

After a moment, the pod shot forward, pinning them to their seats. The trajectory was straight at first, then the whole pod seemed to rotate to the side and tilt, rolling this way and that as they navigated the tunnel.

“How does it work?” Prue asked.