The new graded readers series of original fiction, adapted fiction and factbooks especially written for teenagers. Further adventures for twins Andy and Mary (A Little Trouble in Amsterdam, Level 2). This time Andy and Mary, are away with their father in the beautiful Yorkshire Dales in the UK. After discovering a locked door in a supposedly abandoned mine, Mary's curiosity is aroused. What is someone hiding in the mine? And who is the man watching them through the binoculars?