Mrs Sharma, the doctor's wife, is desperate to get out of Trefelin, but when local tearaway Dan gets into trouble, only she can help him. The doctor's friendship with Megan deepens as they realise that the old doctor's diary holds vital clues to the deteriorating health of the local miners. Mine manager Sharpe tries to persuade the Doctor that health hazards are just an unfortunate part of a miner's job, and teenager Gina is falling recklessly in love.