Plot: Could the British Secret Service be linked with a murder that, for nearly 90 years, has been attributed to self-confessed culprit Prince Felix Yusupov? Acting with a group of fellow conspirators, he is said to have poisoned, shot, and finally drowned the allegedly mad monk Grigori Rasputin in the Russian city of St Petersburg in 1916. Former Scotland Yard commander and murder detective Richard Cullen travels back to the scene of the crime to re-examine the evidence