Why is DOCTOR WHO suddenly summoned to the shores of Loch Ness?
Terror and panic spread as the third oil rig is smashed into the sea by a mysterious force... the monster?
The controlling power must be the ZYGONS-alien creatures who have lived hidden on Earth for thousands of years, and now feel strong enough to take over the planet... The Doctor, Sarah and UNIT have different ideas - but can they outwit the supreme cunning of the ruthless ZYGONS?
DOCTOR WHO scripts - awarded The Writers' Guild Award for the best British children's original drama script.