Damned If You Do — Gordon Houghton

Hades is dead and the Agency needs a replacement, a new apprentice to carry on its good work. After a vote, corpse number 72 18 9 11 12 13 49 is selected and promptly yanked from his grave, to serve a seven day trial sentence. Each day our hapless narrator is to assist Death in the killing of one unfortunate soul, but as he encounters each victim, and as he begins to grasp the functions of Death and the other three modern-day Horsemen, he begins to unlock strange memories of his own prior life. It is not until he understands the backhanded politics of the Four Horsemen's run-down row house, and the sinister circumstances of his predecessor's demise, that he can recognize his true purpose in, well, er, life...