Spies and intrigue. Vital dispatches sent through treacherous waters.
The initials of one of the most powerful politicians in the land, etched on a gun lying deep under the sea. A small country, fighting with cutting-edge military technology against a terrifying power.
Hidden treasure sitting undisturbed for four centuries, which divers risk their lives to recover.
And all of it is true. On the Timewatch programme tonight on BBC Two, viewers can see for the first time the events that led to a groundbreaking discovery.
The story begins with the location of a wreck half a mile off the tip of the Channel Island of Alderney, where an Elizabethan ship, heavily armed with cannon, was reported lost in 1592.
Raised from the sea bed four centuries later, the guns and shot led a marine archaeologist to propound a theory that could rewrite English naval history.
A new and tantalising mystery emerged too, prompted by a set of initials found engraved on one of the cannon.
“You do get these moments — I call them ‘mind touch’ — which transport you back over the centuries,” said Mensun Bound, the marine archaeologist and Fellow at St Peter’s College, Oxford, speaking from his 14th-century manor house in the Oxfordshire village of Horspath.