“That’s because you’ve telephoned the sell-by date,” I told him. I turned the carton over. “This is the number here . . .”

And that was how, three weeks later, we found ourselves standing in the lobby of Waterloo station. Tim was carrying the tickets. I was carrying the bags. It had been more than a year since we’d been abroad—that had been to Amsterdam on the trail of the mysterious assassin known as Charon—and that time we had gone by ferry. Tim had been completely seasick even before he reached the sea. I was relieved that this time we were going by train, taking the Channel Tunnel, although with Tim, of course, you never knew.

We took the escalator down to the international terminal. Ahead of us, the tunnel was waiting: a thirty-two-mile stretch linking England and France, built at a cost of twelve billion dollars.

“You have to admit,” Tim said. “It’s an engineering marvel.”

“That’s just what I was thinking,” I said.

“Yes. It’s a fantastic escalator. And so much faster than going down the stairs . . .”

We had two seats next to each other right in the middle of one of the carriages. The train was pretty full and soon we were joined by two other passengers opposite us. They were both traveling alone. The first was from Texas—you could tell just from his hat. He was chewing an unlit cigar (this was a nonsmoking compartment) and reading a magazine: International Oil. The other passenger was a very old lady with white hair and skin so wrinkled I was amazed it managed to stay on. I wasn’t sure if she had huge eyes or extremely powerful glasses but every time she looked at me I thought I was about to be hit by a pair of gray-and-white golf balls. I looked out of the window. The platform was already empty, sweeping in a graceful curve beneath the great glass canopy. Somewhere a door slammed.

The train left exactly on time at ten minutes past ten. There was no whistle. No announcement. I wouldn’t have known we had moved if it hadn’t been for the slight shudder—and even that was Tim, not the train. He was obviously excited.

About an hour later there was an announcement on the intercom and we dipped into the tunnel carved out underneath the sea. That was a nonevent, too. A parking lot, a sign advertising hamburgers, a white cement wall, and suddenly the outside world disappeared, replaced by rushing blackness. So this was the engineering miracle of the last century? As far as Eurostar was concerned, it was just a hole in the ground.

Tim had been ready with his camera and now he drew back, disappointed. “Is this it?” he demanded.

I looked up from my book. “What were you expecting, Tim?” I asked.

“I thought this train went underwater!” Tim sighed. “I wanted to take some pictures of the fish!”