Christie A. <br/><br/>
The Secret Adversary 

 - New York:  Bantam Books,  1950. 
 - 215 p. 
<br/><br/> n/29553 
<br/><br/> His name is Mr. Brown. No one looks at him twice: his face is every bit as ordinary and unmemorable as his name. He shows up in the oddest places as Brown the office clerk or Brown the Scotland Yard detective. And always he is almost totally unnoticed and devastatingly effective. He is without doubt the finest and the most ruthless criminal mind of the century.