In August 1915, in the middle of the Gallipoli campaign, a group of volunteer soldiers from George V’s Sandringham estate advanced into enemy territory… and simply disappeared.

This 1999 feature-length drama made with BBC cash and boasting a great cast – David Jason, Maggie Smith and Patrick Malahide are just three standout names – sets about unpicking one of the great and long-standing mysteries of World War One.

Those hoping for a supernatural explanation might be disappointed, but the Sandringham locations ground the drama in reality and help move things towards the emotional finale.