Sir Malcolm Campbell (played by Alex Lowe), the famous racer is practicing on Loch Ness for an attempt on the water speed record but disappears along with his boat in a mysterious bank of fog. MI:13’s Harry Crow (David Warner) and Professor Dunning (Terry Molloy) go up to the loch-side village of Inverfarigaig to investigate. Aided by the local GP Dr Pippin (Philip Madoc), they discover a connection to the former "Laird of Boleskine and Abertarff" - the occultist Aleister Crowley (David Benson). Joined by Crowley, the investigations into Sir Malcolm’s disappearance lead them into terrible danger, and an encounter with an old foe
