Back For More (Infected Voices #6) by Robert Essig

The lights are bright to show everything in vivid detail. There are whips and chains and floggers and thumb cuffs and spikes and nail-studded paddles, and . . . oh shit . . . The isolation. The pain. The torture. The blood. The agony!

Most people are thankful to be alive after such an ordeal.

Some people come back for more.