At first, it was just like being in a tunnel. Darkness all around, while a single old-fashioned spirit lamp filled the cab with a warm golden glow. The only sound was the roar of Ivor’s powerful engine as we plunged on into darkness. And then, one by one, the stars began to come out; in ones and twos, then in dozens, then in thousands, until we were surrounded by great surging oceans of light. Now it was like passing through outer space, but nowhere any astronaut had ever seen. Instead of familiar constellations, there were great seas of stars, blazing with a light almost too pure and beautiful to bear. Comets sailed past Ivor, brightly coloured, like the sweets we loved as children, sweeping past in elegant arcs that contrasted sharply with the steady surging progress of Ivor the Time Train.

Strange planets passed us by, weird and uncanny, that had no place in any natural solar system.

“If this is outer space,” Molly ventured, “and I’m quite prepared to be told that it isn’t . . . how come we’re able to breathe?”

“Ivor has many talents and many secrets,” Tony said grandly. “You are quite safe, Miss Molly, as long as you stay inside the cab.”

“But where . . . exactly, are we?” I said.

Tony shrugged. “I’ve read all the books, but I have to say no one seems too sure of exactly what it is Ivor travels through. My grandfather, the last man to actually take Ivor out, said that this is what time and space look like, seen from the other side. Whatever that means. There are other theories, suggesting that Ivor travels through the universe below ours. Or possibly the one above. Believe whatever makes you feel safest, that’s what I say.”

I looked at Molly. “Conversations like this are why the family prefers to leave time travel strictly alone.”

“Pah!” said Tony. “They have no sense of adventure!”

“Hold everything,” said Molly. “What is that?”

We all looked where she was pointing. A great yellow shape was sweeping rapidly through the starry night, heading straight for us. As it grew closer, it revealed itself to be a huge yellow dragon. Disturbingly large, a hundred times the size of Ivor, it was a garish banana yellow in colour, with sickly pink markings up and down its long body. The head was blunt and bony, with a row of glaring red eyes set above a gaping maw packed with jagged, sharklike teeth. Vast membranous yellow wings bellowed out on either side of the bulging midsection. It had short grabbing arms set on the neck below the mouth, armed with vicious, curving talons. The dragon shot past us, silent as a nightmare, the massive wings barely flapping. The head turned to follow us, on the end of a long serpentine neck, and up close the head alone was bigger than Ivor.