After the fluorescence of Frieze, last night’s cloistered and barely candlelit opening of Venus Over Manhattan was a shock to the art system. The new gallery at 980 Madison Avenue is the latest passion of Adam Lindemann, and if it seems strange for an art writer and collector to turn dealer at age 50, well, strangeness is part of the aim. “I was fascinated with the novel À Rebours,” Lindemann said, referencing Joris-Karl Huysmans’ decadent classic.