“Yes, yes, yes,” Miss Rosalie said, so obviously humouring him that Gabriel began rolling about in distress, spilling bedclothes on to the floor. “Of course I’ll warn them,” Miss Rosalie said, hauling blankets back. “Settle down, Gabriel, before you make yourself ill, and we’ll do everything you want.” She made meaning faces at Mr Roberts to take Cat and Tonino out of the room.

Mr Roberts nodded. He put a hand on each boy’s shoulder and steered them out on to the landing. Behind them, as he gently shut the door, they heard Gabriel say, “Listen, Rosalie, my mind is not wandering! Spiderman has learnt to travel in time. He’s dangerous. I mean what I say.”

Gabriel de Witt sounded so weak and so upset that Mr Roberts said, looking extremely worried, “Look, I think you boys had better go home now. I don’t think he’ll be well enough to talk to you again today. I’ll call you a cab and telephone the castle to say you’ll be back on an earlier train.”

There was nothing Cat wanted more by this time. Tonino, from the look of him, felt the same. The only thing Cat regretted was that they were going to miss lunch. Still, Miss Rosalie’s idea of lunch was usually a tomato and some lettuce, and they did have Millie’s five shillings. He followed Mr Roberts downstairs thinking of doughnuts and station pies.

Luckily there was a cab just clopping along the road as they reached the front gate. It was one of those old-fashioned horse-drawn hackneys, like a big upright box on wheels, with the driver sitting up on top of the box. It was shabby and the horse was scrawny, but Mr Roberts hailed it with strong relief and paid the driver for them as the boys climbed in. “You can just catch the twelve thirty,” he said. “Hurry it along, driver.”

He shut the door and the cab set off. It was smelly and jolting and its wheels squeaked, but Cat felt it was worth it just to get away so soon. It was not far to the station. Cat sat back in the half dark inside the box and felt his mind go empty with relief. He did not want to think of Gabriel de Witt again for a very long time. He thought about station pies and corned beef sandwiches instead.

But half an hour of jolting, smelling and squeaking later, something began puzzling him. He turned to the other boy in the dimness beside him. “Where were we going?”

Tonino – if that was his name: Cat found he was not at all sure – shook his head uncertainly. “We are travelling north east,” he said. “I feel sick.”

“Keep swallowing then,” Cat told him. One thing he seemed to be sure of was that he was supposed to look after this boy, whoever he was. “It can’t be that far now,” he said soothingly. Then he wondered what, or where, was ‘not far’. He was a little puzzled to find he had no idea.