As was the custom in London, the scaffolding had been let out to some enterprising bill-posting company. It was a mass of gaudy sheets and placards puffing a variety of different kinds of wares. In the centre, bordered by a deep band of black, was one solitary yellow face with dark hair and starting eyes. At the base was the single word "Nostalgo."
An extraordinary vivid and striking piece of work for a poster. The face was strong and yet evil, the eyes were full of a devilish malignity, yet there was a kind of laugh in them too. Artists spoke freely of the Nostalgo poster as a work of positive genius, yet nobody could name the author of it. Nobody knew what it meant, what it foreshadowed. For two months now the thing had been one of the sensations of London. The cheap Press had built up legends round that diabolically clever poster; the head had been dragged into a story. The firm who posted Nostalgo professed to know nothing as to its inner meaning. It had become a catchword; actors on the variety stage made jokes about it. But still that devilish yellow face stared down at London with the malignant smile in the starting eyes.
"Jack, they have put up a fresh 'Nostalgo' poster on the hoarding opposite," Claire said. "I wish they hadn't. That face frightens me. It reminds me of somebody."
"So it does me," Jack replied, with sudden boldness. "It reminds me of your guardian."
Claire smiled at the suggestion. The guardian was a large, florid man, well-groomed and exquisitely clean. And yet as Jack spoke the yellow face opposite seemed to change, and in some way the illusion was complete. It was only for an instant, and then the starting eyes and the queer smile that London knew so well were back again.
"You make me shudder," Claire said in a half-frightened way. "I should never have thought of that. But as you spoke the face seemed to change. I could see my guardian dimly behind it. Jack, am I suddenly growing nervous or fanciful? The thing is absurd."
"Not a bit of it," Jack said stoutly. "The likeness is there. It may be a weird caricature, but I can see it quite plainly. Don't you recall how Anstruther breaks out into yellow patches when he is excited or angry? I tell you I hate that man. I may be nonsensical, but----"
Jack paced up and down the room as if lost in thought. The light was shining on the face on the hoarding--it seemed to look at him with Spencer Anstruther's eyes.
"There is something wrong in this house," he said. "I feel it. You may laugh at me, you may say that I am talking nonsense, but there it is. The strange people who come here----"
"Sent by the police mainly. Don't forget that my guardian is one of the greatest criminologists of our time. There is no man in London who can trace the motive of a crime quicker than Mr. Anstruther. There was that marvelous case of those missing children, for instance----"