The novel, set in 1918, describes how Charles Dexter Ward becomes obsessed with his distant ancestor, Joseph Curwen, an alleged wizard with unsavory habits. Ward physically resembles Curwen, and attempts to duplicate his ancestor's Qabalistic and alchemical feats. He eventually uses this knowledge to physically resurrect Curwen. Ward's doctor, Marinus Bicknell Willett, investigates Ward's activities and is horrified by what he finds.