Once again detective ''Hank'' Hankenson is forced to play a deadly mind game with a diabolical serial killer, when the body of a high-profile fund raiser for the arts community in Minneapolis is discovered within the giant contours of the Spoon Bridge and Cherry in the Walker Arts Center Sculpture Garden. Soon after, the famed Guthrie Theatre and the Minneapolis Institute of Arts become killing sites as well. Hankenson's hunt for the killer eventually extends to the fabled Kensington Runestone purported by scientists to have been left in central Minnesota by Vikings prior to Columbus coming to America. Most of the characters from Rueff's mystery thriller, Endgame, are back: the ''Rifleman'' vigilante whose murky identity is revealed in Mind Game; the enthralling, stand-offish advertising executive, Darcy Austin, who became Hankenson's lover; Caren Dalton, Darcy's nemesis with a grudge yet to settle with her; and the enigmatic Josh Williams with his cast of comic-book characters that intertwine with real life ... and real death.