It's been many months since the Doctor was in Hexford, and Mrs Wibbsey keenly feels his absence. As her grave suspicions about her new neighbour grow, she is in danger of becoming ostracised from village life. When Mike Yates turns up at Nest Cottage with a visitor in tow, Mrs Wibbsey's life is turned even further upside down. Why has this strange new fellow appeared - and can he really be who Mike thinks he is?
With UNIT watching the skies, and a strange forest growing daily around the village perimeter, it comes as little surprise when an enormous spaceship slides into view and dominates the skyline. Who is watching Hexford, and what do they want? Never has Mrs Wibbsey needed the Doctor more. But can she cope with two...?