Somewhere on the seabed of the Atlantic ocean lie two casualties of the Second World War: a Japanese submarine, the I-52 and the liner SS Aurelia. Separated by almost a thousand miles of ocean and sunk more than fifteen months apart, these two vessels have one thing in common - they were both carrying several tons of gold. In October 1994, James Hamilton-Patterson was invited to join Project Orca, a team of people who set out to try and find the wrecks and the gold. This book is so much more than a tale of a hunt for 'filthy lucre'. James Hamilton-Patterson gives one of the rare eye-witness accounts by a non-scientist of what it is like to free-fall to the seabed for three hours in a tiny sphere two metres in diameter, and spend the next fourteen hours drifting about in a lightless world of dunes and outcrops. It is thus a priviledged view of a primordial world full of unexpected beauty and resonance: an eerie but awe-inspiring world of shadows.