Secrets and lies are dangerous. When Jacques's body is discovered in a hotel room his wife, Patricia, suspects he has been hiding something from her. Why was he found naked and who is the woman that visited his grave on the day of the funeral? Significantly, who is the unnamed beneficiary Jacques left a large sum of money to in his will and what is the reason her best friend, also Jacques's sister, Coco, refuses to tell her what he confided to her? Struggling to find out the truth, Patricia visits Malmö where her twin sister Jasmine lives and is married to her ex boyfriend. But the sisters relationship is toxic and when a family member dies shortly after, an old secret is revealed that shines a light on an event that took place on their tenth birthday. As one revelation after another is revealed, Patricia is yet to discover her husband's biggest secret and what ultimately cost him his life. His Guilty Secret is an unafraid examination of the tangled bonds between siblings, the lengths we go to in protecting our wrongdoings, and the enduring psychological effects this has on the innocent... and the not so innocent.