“I think I see them.”

The young man in the green parka standing directly beneath the huge circular clock in St. Pancras station took the phone away from his ear and checked a blurred image on the screen. The English Magician had sent the image: the picture was grainy, the colors washed and faded, and it looked liked it had been taken from an overhead security camera. It showed an older man with short gray hair, accompanied by two blond-haired teens, climbing onto a train.

Rising up on his toes, the young man swiveled his head, looking for the trio he’d glimpsed. For a moment, he thought he’d lost them in the milling crowd, but even if he had, they wouldn’t get far: one of his sisters was downstairs; another was in the street outside, watching the entrance.

Now, where had the old man and the teenagers gone?

Narrow, pinched nostrils opened wide as the young man sorted through the countless scents in the station. He identified and dismissed the mixed stink of too many humani, the myriad perfumes and deodorants, the gels and pastes, the greasy odor of fried food from the station’s restaurants, the richer aroma of coffee and the metallic oily tang of the train engines and carriages. He closed his eyes and tilted his head back.

The odors he was seeking were older, wilder, unnatural. . . .

There!

Mint: just the merest suggestion.
Orange: no more than the vaguest hint.
Vanilla: little more than a trace.

Hidden behind small rectangular sunglasses, blue-black eyes opened wide and his head swiveled, following the gossamer threads of scent through the vast train station. He had them now!

The gray-haired older man, wearing blac...