A Shock to the System — Simon Brett

An ambitious executive is motivated by malice and murder in this darkly comic Edgar Award�"nominated thriller by the author of the Charles Paris mysteries.
 
Graham Marshall is a respectable husband and father and dedicated London businessman. He's always played by the rules, believing that's the surest way to climb the corporate ladder. But when he's passed over for promotion by a ruthless colleague, something snaps. On a drunken walk home late that night, Graham unleashes his fury on a hapless panhandler and dumps his body into the Thames. As days pass for the anxious exec, he realizes to his astonishment that he's gotten away with murder. And it appears to be much easier than anyone's been led to believe.
 
Feeling more powerful than he has in years, Graham now has his eyes on the future -- and on everyone who stands in his way, professionally and personally. It might have all begun with a terrible accident. But for Graham, his new objectives are entirely by design.
 
“A crisp, chilly tale of murder . . . extra-dry in its humor.” -- Kirkus Reviews