First, she lost her son. Then she lost her trust. Now she's about to lose control. Ten years ago, bestselling author Olivia Collins's life shattered when her teenage son collapsed and died. Her marriage survived the grief. Her career did not. Now, just as she starts to rebuild, Olivia stumbles on something she wasn't meant to find: a hotel key card, a woman's name, and a lie that began the day her son died. What starts as quiet suspicion soon spirals into obsession.

As Olivia investigates her husband's past, she uncovers a chain of betrayal, deceit and a devastating secret tied to the worst moment of her life. When tragedy strikes again, Olivia must decide whether to forgive, walk away or get even. Because in a house built on lies, someone always pays the price - and she has nothing left to lose. Twisting, chilling, and compulsively readable, The Other Mrs Collins is a psychological thriller about marriage, motherhood, and the quiet fury that turns grief into revenge.