Knowing intellectually the theoretical inaccuracy of a pistol over a distance of several hundred yards is not the same as knowing one is safe: We all three dove behind the nearest large object until the shot had ceased echoing down the street and the screams and rushing about had started. Three heads slowly emerged, in time to see our quarry climb into a maroon-coloured Chrysler whose terrified driver, hands high in the air, stood in the street and watched his vehicle race off up the Embarcadero without him.

Holmes and I looked at each other, grimaced, and pulled out our own revolvers to commandeer a jazzy green open motor that, although nowhere near as powerful as the Chrysler, was low enough to corner well. Rather to my surprise Hammett, although he appeared eager to stay with us, made no move to shoulder me aside, but threw himself in the backseat so that I might leap behind the wheel. With Holmes shouting thanks and apologies at the man we left behind, I slammed my foot onto the accelerator.

North of Market, the Embarcadero is wide, flat, and straight; they saw us coming before we had gone half a mile. Greenfield accelerated and I did the same, and it looked as if we would keep on at this speed until we flew off the first curve into the Bay or crashed into the walls surrounding Fort Mason. Then abruptly he swerved left and shot into the maze around Telegraph Hill.

“Hah!” came a voice from the back; Hammett leant forward over my shoulder and said, “If they don't know the area, we may have them.”

Telegraph Hill loomed ahead of us, too steep for roads on this side, but the motor ahead of us dodged and scurried around its base, avoiding the dead-ends by skill or luck. I kept us on the road and in sight of them, using my horn freely, grateful that this was not an area with heavy traffic. Although we hadn't their engine power, we were better on the corners, and as I grew accustomed to the steering I managed to gain on them a little. We screamed around corners within a hair's-breadth of parked cars and lamp-posts, using the brakes almost not at all; slowly, the maroon motor's number-plate grew ever closer.

I had no idea where I was, and no time to ask. Instead I shouted over my shoulder, “If you have any knowledge of the streets you wish to impart, please feel free.”

Hammett said only, his voice tight, “You're doing fine.”

After several minutes of circling and dodging through the residential streets, suddenly we were back on the Embarcadero, heading south this time, back towards the Ferry Building. Just before he entered the snarl of traffic there, Greenfield flew to the right, taking some paint off a cable-car, dodged north for a couple of streets, then west. He swerved around a horse-drawn wagon, then with a sharp squeal of tyres shot directly across the nose of a taxi and entered a street I knew all too well.