Marya Zelli is the novel’s emotional center: a woman living in Paris after leaving England to marry Stephan Zelli, and already socially and economically precarious before the Heidlers take hold of her life. She is vulnerable, observant, often passive on the surface, yet painfully aware of humiliation and dependency; her tragedy is not simple innocence but the way isolation, poverty, and desire keep compromising her ability to act freely even when she recognizes the danger around her.

Stephan Zelli is not a later rival but Marya’s husband, erratic and unreliable, whose imprisonment exposes how fragile their life already is. H.J. Heidler enters that vulnerability as seductive, paternal, manipulative, and most dangerous when he appears generous, while Lois Heidler is not merely a bystander but a cool, socially disciplined presence whose knowledge, jealousy, and accommodation help stabilize the arrangement. Together they form the novel’s quartet of need, arrogance, possession, and failed protection.