Horror of Fang Rock, Part One

Résumé :

The TARDIS lands near an isolated rocky island lighthouse just after a comet strikes the nearby sea and a sudden chilling fog rolls in. Soon after, electrical problems take hold of the generator and one of the keepers dies mysteriously. Rueben, the eldest keeper, thinks it's the return of the legendary Beast of Fang Rock, but the Doctor suspects it's something worse that a legend.