Reagan Keating has been murdered. Gemma soon discovers that Reagan's death is the second tragedy in this exclusive London park. Meanwhile, Kincaid finds himself plagued by disturbing questions about several previous - and seemingly unrelated - cases involving members of the force. As Gemma begins to see a solution to her case, she realizes she holds a child's fate in her hands. Can she do the right thing? And can Kincaid rely on his friends, both inside and outside the Scotland Yard force, to stand beside him as he faces the deadliest challenge of his career?