FOREWORD
When I showed this manuscript to my friend, Chief Detective-Inspector Alleyn, of the Criminal Investigation Department, he said:
“It’s a perfectly good account of the Unicorn case, but isn’t it usual in detective stories to conceal the identity of the criminal?”
I looked at him coldly.
“Hopelessly vieux jeu, my dear Alleyn. Nowadays the identity of the criminal is always revealed in the early chapters. ”
“In that case,” he said, “I congratulate you.”
I was not altogether delighted.