The Truant Soul plot
Dr. John Lancaster is a great surgeon, a man of fine instincts, but one with a hidden second nature. He performs miraculous operations. He does incalculable good for humanity. But sudden periods of temporary atavism come over him, and he reverts to his primitive nature. He sinks into the lowest forms of vice. He is cruel, heartless, vengeful, and unscrupulous. He blows up lives and loves without remorse. As this strange reversal reaches its climax and death or a madhouse seems the surgeon's inevitable demise, Joan Wentworth, a nurse, enters his life.