London's wealthiest, poorest, kindest and most dangerous citizens all cross paths in Regent's Park. All it takes to bring them together is a series of brutally gruesome murders...

Mary Jago has donated her bone marrow to save the life of a complete stranger; a generous act of kindness that culminates in a horrible break-up with her abusive boyfriend.

Moving to the affluent edge of London's famous Regent's Park, Mary believes she has finally escaped the threat of violence. She never thought that one simple act of kindness could put her own life in mortal danger...