But the two killers weren’t going to let us get away quite so easily. I glanced back and saw them pushing their way through the crowd. Bastille shoved out a hand and one of the tourists, an elderly woman, shrieked and fell backward into a fountain. Several of the other tourists stopped and took photographs of her. Bastille stepped into the road. A car swerved to avoid him and crashed into the front of a restaurant. Two lobsters and a plateful of mussels were sent flying. Someone screamed.

It still wasn’t dark. The streets were full of people on their way to restaurants, too wrapped up in their own affairs to notice two English visitors running for their lives. I had no idea where I was going and I wasn’t going to stop and ask for directions. I grabbed Tim again and steered him up an alleyway with dozens more restaurants on both sides. A waiter in a long white apron, carrying several trays laden with plates and glasses, stepped out in front of me. There was no way I could avoid him. There was a strangled cry, then a crash.

“Excusez-moi!” Tim burbled.

Fortunately, I didn’t know enough French to understand the waiter’s reply.

The alleyway brought us back to the Seine. I could see Notre Dame in the distance. Only a few hours before we had been standing on one of its towers, enjoying the view. How could our vacation have become a nightmare so quickly?

“This way, Tim!” I shouted.

I pulled him across a busy street, cars screeching to a halt, horns blaring. A policeman turned around to face us, a whistle clenched between his teeth, his hands scrabbling for his gun. I swear he would have shot us except that we were already on the other side of the road and a few seconds later Bastille had reached him, brutally pushing him out of the way. The unfortunate cop spun around and collided with a cyclist. Both of them collapsed in a tangle of rubber and steel. The last I saw of the cop, he had gotten back to his feet and was shouting at us, making a curious, high-pitched noise. Evidently he had swallowed his whistle, which had now gotten lodged in his throat.

The river was now right in front of us with a pedestrian bridge leading over to the other side. Bastille and Lavache were already crossing the road, blocked for a moment by a bus that had slipped in between them and us.

“The river!” I said.

Tim reached into his pocket and took out his camera.

“No!” I yelled. “I don’t want you to photograph it! I want us to cross it!”