Michael and his father, the former Lord Chamberlain Søren Haslund-Christensen, are in the attic to find hidden treasures from the past. Michael's grandfather Henning was a famous explorer and collector of cultural heritage from Mongolian tribes, and Michael has heard rumours that Henning lived a double life as a British agent and arms smuggler. Now he wants to find out if this is true. He also wants to spend some time with his father, as Søren's health is in decline and time is running out. He has lured his father to join him on an adventure both like and unlike the ones they have been through so many times in their life before, on a journey in his grandfather's footsteps. A journey which goes back in time to a story about love and loss, and to a spectacular espionage plot in the time around the Second World War, which involved both his grandfather Henning and the fight of powerful empires for global dominance. 'The Great Game' is a family chronicle, an epic work and not least a film about fathers and sons in a family that is more adventurous than usual.