The Wrong Sister by Claire Douglas is a suspenseful thriller that unravels family secrets and forbidden emotions, blurring the lines between loyalty and desire. The story centers on Frankie, who returns to her coastal hometown to support her family after the sudden death of her sister, Rachael. As she reconnects with Rachael's husband, tensions rise, and she begins to suspect that Rachael's death may not have been accidental. With complex characters and a dark, twisting plot, the novel explores the dangers of hidden truths and unresolved grief.