House of Darke — Colin R. Parsons

Zade, Tina, Pip and Meadow are four teenagers enjoying an end-of-summer bike ride -- that is until a mist descends, leaving them stranded at a picnic area in the middle of the countryside. What can they do? The grey fog is dense and they can't see a metre in front of them. They abandon their bikes and set off to seek help. Finding shelter by way of the secluded country house owned by the wealthy and charming Lord Epacseon Darke, they had no idea what would happen next. Welcome to House of Darke -- enjoy your stay!