Erismore was an isolated small island in the Inner Hebrides and Finlay MacBride had been the Church of Scotland minister – but before he followed so many of the island's men to the colours, he had been aware that not all was well on the island. Aeneas Graham, serving as a doctor in Wellington's army, had made friends with Finlay MacBride who was attached to Lord Dunalastair Highlanders in the army. Lord Dunalastair was killed at Quatre Bras. Just before the battle of Waterloo, during a retirement of the army, Finlay Macbride became fatally ill and before he died asked his friend to visit his sister in Edinburgh and also to visit the new Lord Dunalastair to plead for another minister to be sent to Erismore to replace him. Finlay said that the Devil had his claws in Erismore. Aeneas followed his friend's wishes and the gripping tale ensues.