Does the grisly discovery of human remains in a Siberian forest spell the end of one of the most enduring – and perplexing - mysteries of the twentieth century?
In the early hours of July 17th 1918 a volley of shots ended the Russian Romanov dynasty. A Bolshevik firing squad murdered the last Tsar, Nicholas II, his wife, his young son and his four teenage daughters. Or did they? For nearly a century,  rumours have persisted that at least two of the children – Crown Prince Alexei and Grand Duchess Anastasia - escaped.
For National Geographic’s prestigious Explorer strand, this film follows the international investigation in which the Kremlin and the Pentagon team up to close the chapter once and for all on this royal cold case.