We'd have been well and truly wrecked if the lad said he'd just decided to ride the street-car on a whim, I reflected, but he was nodding. “They got off down near Sixteenth, went into a hotel and walked right out again about two minutes later with a coupla bags, and got onto another trolley going the other way. I left Kurt there to tell Ricky.”

“He found us,” Holmes reassured him, handing over the shiniest coin yet, this one an entire silver dollar. “We'll let you out here, lad. And you tell your friends that they should bring their appetites with them in the morning. I'll buy you all the biggest breakfast the St Francis serves.”

The boy's expression indicated that he did not often dine in establishments such as the St Francis, and we left him on the pavement, staring in wonder at our retreating vehicle.

We had the driver dawdle far enough back from the trolley so that our coinciding stops and starts might not attract the attention of the passengers, yet near enough that, if the two spotted us and attempted to fade into the downtown crowds without their bags, we might see them. But no one resembling the man and woman in the photograph Flo had given me descended from the trolley, and it continued up the die-straight path of Market in the direction of the Ferry Building.

The street-car reached the wide boulevard of the Embarcadero, onto which all the piers opened, and entered the turn-around in front of the Ferry Building. The afternoon traffic made for a positive ant-hill of taxis, private cars, bicycles, hand-trucks, and pedestrians. We waited, holding our collective breath, until we saw a man and a woman step down to the street, each carrying a valise; the man's hat was pulled down to hide his face. Holmes slapped some money into the driver's hand and the three of us got out as quickly and as smoothly as we could, trying not to look as if we were interested in anything much, closing casually but rapidly on the terminus.

But the woman spotted us. We were not exactly unobtrusive in a crowd, as even slumped into their coats, Holmes and Hammett towered above everyone else, and I am not far behind. She looked back and she spotted us and grabbed her companion's shoulder; he whirled around, looked straight in our direction, then seized her by the arm and ran, abandoning the two valises on the street. We ran, too, dodging through the traffic to the music of furious horns and the whistles of two outraged policemen, and gained the pavement in time to see the man pull a revolver from his pocket and aim it in our direction.