Morgan and Cumbersomething, two old army friends of Professor Fotheringshaws pop in to the newly formed cryptozoology department on an april afternoon, the brandy starts flowing as do the stories and soon Fotheringshaw has got his special photograph collection out. Several other members of the department are also in the building, Victoria a young classics graduate who has been translating some old texts, Augustus a sceptical young grad student who is assisting the professor in order to receive some extra credits and Stevenson an engineer has dropped by to discuss the sale of several specimens he has brought back from India. It is not your average slide show however and the disturbing contents of the photographs cause several present to lose a couple of sanity points.
While the six discuss the photographs a commotion is heard downstairs and a rather smartly dressed gentleman Detective McEwen from the Glasgow Constabulary has shown up investigating the apparent suicide of Sir George Bullough Apparent Suicide of Millionaire Landowner the millionaire playboy and land owner, who Professor fotheringshaw has had dealings with in the past. Bullough has disappeared from his yacht leaving a suicide note but before doing so he has carved the names of the investigators who were previously involved on the isle of rum into the wheelhouse desk.
The players are convinced by Detective McEwen to come to check out the boat now docked at Inverkip marina at the mouth of the clyde and are instructed to meet at the department at 7am sharp. McEwen is a little concerned that the other five investigators who were on Rhum with Fotheringshaw are all either missing or dead.
That night all six of the investigators have a similar strange dream where they are deep underground in a stone chamber standing and chanting in a circle surrounding a deep hole. Victoria tries to paint the scene in the morning but her art does not turn out as she had hoped.
The journey from Edinburgh to Inverkip is uneventful and when they arrive at the yacht they notice a reporter Andrew Gordon from the Glasgow herald is trying unsuccessfully to gain access to the yacht. Once onboard the investigators enter the wheel house to a horrific scene. Strange characters and symbols have been written all over the walls and desk in blood and the Bullough Suicide Note is pinned to the desk by a large carving knife.
After closer inspection of the characters by Victoria they quickly become apparent as a crude imitation of occult symbols. Cumbersomething identifies the blood as cows blood and the whole set up is extremely fishy to say the least. Stevenson has an unnerving feeling of being watched while on the boat so decides to leave and try to speak with the reporter on the shore.
Meanwhile Augustus spots a bald man on another vessel and alerts the two soldiers who head off in pursuit. After having a cagy conversation with the reporter Stevenson heads back down to the dock, he bumps into the bald man coming the other way and recognises him as Isaac Hart. Stevenson tries to communicate with the man but gets no reaction until he mentions Fotheringshaws name. Hart is initially hesitant but proceeds to punch Stevenson in the gut winding him, he goes to knock him out but is interrupted by the two soldiers who have sneaked up on him. He flees and Cumbersomething stops to assist Stevenson while Morgan takes off after Hart. After a brief chase a fist fight ensues and Hart knocks out Morgan and breaks his nose with a punch to the face and disappears by the time Cumbersomething arrives on the scene.
Victoria then tracks Harts footsteps to a small b&b on the outskirts of town, it appears he has assaulted the old woman who runs the b&b before speeding off towards Glasgow on his motorbike. Morgan consoles the old woman and plies her with brandy as the others uncover 4 hunks of human flesh wrapped in a 3 day old Inverness courier newspaper. They also find an unopened Telegram for Hart simply instructing him to return to Inverness. The investigators conclude that the fastest way to get to Inverness for hart would be by train so they endeavour to try and catch the afternoon train to Inverness as well. Having no form of transport they quickly fast talk one of the police men into letting them borrow his vehicle and head off siren wailing back down the Clyde to Glasgow. A flat tyre and some quick repair later they arrive at the station just as the train is pulling in. They decide to abandon the rifle as it is two big to conceal but armed with several side arms and a hidden shotgun they all board the train for Inverness.