Ian Hay, The Widow's Cruise (1910)
“ At first sight you would have taken him for an English lawyer of sporting proclivities. His name was Killick, and he was one of the mainsprings of that great organization which has its centre in Scotland Yard. Beside him stood a subordinate, and scattered through the crowd were others—unobtrusive individuals known as plain-clothes men. The passengers began to file down two great gangways, Killick scrutinized the stream with an eye that took in every face, every trick of voice and gesture. ”
