Evelyn Fergusson had rung Isobel the day before and left the telephone number of someone who might be of use to Marnie. She’d been making some enquiries through old acquaintances, she said, and thought that the Reverend Donald McBain, the retired minister of the now redundant kirk at Wester Finterie, might be able to help them. ‘Tell Marnie that he’s an old man now, but he probably knew the family, and apparently is likely to have information about what’s happened to the house and whether there’s anyone living there now. He might even know how to get hold of a key. Tell Marnie to give him a ring. Do mention Tillydrum and say I suggested it because I believe he once came here as part of a gardening group.’

Christopher had been relieved at this bit of information. His heart had sunk when Marnie, colourful notions floating around her head, had told him she remembered the old lady telling her how she and her brother had a secret hiding place in a wall beneath a particular window where they kept a key to a little-used door, so that they could go on expeditions at night and get in again undetected by the grown-ups. There had been forbidden rabbiting excursions, without the keeper to supervise them; they had gone trolling for trout on the loch by moonlight; they had lit a bonfire in the woods and tried to bake potatoes but had only ended up with lumps like charcoal. ‘Imagine! Wouldn’t it be exciting if the key was still there,’ said Marnie, starry-eyed, ‘and we could let ourselves into the castle without anyone knowing?’

‘Too exciting by half!’ said Christopher, laughing at her. He was entertained by her enthusiasm for such a farfetched idea, while knowing that no matter how much such romantic trespassing might appeal to his companion, in the unlikely event of finding such a long-hidden key – and he had an uneasy suspicion it was just the sort of farfetched thing that might actually happen to Marnie – he could not possibly risk being found ‘breaking and entering’ while still on licence. He had visions of creeping down secret tunnels, activating unseen burglar alarms, and then feeling the heavy hand of a local policeman descend on his shoulder, to be followed by an uncomfortable trip south, not in Marnie’s dashing little blue Audi, but ignominiously handcuffed in the back of a police van. He hoped Marnie wouldn’t have cause to write him off as a dreary old killjoy, when he would so much prefer to be her knight in shining armour.