Tina has tea with the pastor. He tells of casting out a demon called a “lloigor”.
Meanwhile, beneath the castle, Elaine talks to her father in the dark. A tremor shakes the ruins. Malcolm is attacked by a vortex.
Detective Carmichael is recalled to Inverness. In the pastor’s library, Malcolm reads how Castle MacLaireag was destroyed by an accidental explosion. Markus sees the lloigor in his dreams.
Elaine is not well. Malcolm looks after her but her physical and mental health declines.
Markus and Tina go boating. On the island, they find a fob watch and signs of a struggle. Returning through the centre of the pentagon, the boat capsizes. Tina is attacked by something huge beneath the water but is rescued by Markus.
Malcolm acquires dynamite to topple a standing stone. He recalls his wartime instruction by an expert sapper. He follows it to the letter but there is no explosion. He walks over to see what the problem is.
Grieving the loss of their friend, Markus and Tina wait for the night of Samhain. The MacAllans walk into the loch and are swept into the void but Elaine is rescued.
Despite objections from the Historical Society (and damage to their reputation), Markus and Tina engage workmen from Inverness to pull down and break up the stones.