When Sofie James agreed to meet her old friend Kate for a catch-up, she never imagined it would drag her back into the darkest moment of her life - the suspicious death of her father on a Dorset railway track. The official verdict was “accidental”. Sofie has spent months convincing herself it was true. Then Kate drops a bombshell: Sofie’s father was part of an illegal drug trial, and two whistleblowers want to talk. Against her better judgment, Sofie agrees to meet them on a Thames party boat filled with political donors, hired hostesses, and a rising-star MP with everything to lose. It ends in tragedy. Barely escaping with her life, Sofie becomes the only surviving witness to a killing no one wants to believe happened. Forced into hiding, she crosses paths with Cal Harrison, an ex-army surveillance specialist hired to protect the very men who died. Cal knows he’s been lied to. Sofie knows someone wants her silenced. Together, they uncover something far bigger than a botched drug trial: a political conspiracy stretching from London to Africa, built on secrets, suicides, and a drug that drives its victims to madness. But Sofie isn’t just running for the truth - she’s running for her life. Fast-paced, addictive, and packed with twists, The Girl on the Boat is a gripping British conspiracy thriller perfect for fans of Harlan Coben, Robert Harris, and J.P. Delaney.