A young couple staying in an isolated vacation home are terrorized by three unknown assailants.

Untold and lost history. A true story of the American Pathfinders, the volunteer paratroopers whose deadly mission was to land 30 minutes before the Normandy invasion, locate and mark strategic drop zones and set up the top-secret navigation equipment needed to guide the main airborne assault on D-Day.

Sarah Taylor, a police psychologist, meets a mysterious and seductive young man, Tony Ramirez, and falls in love with him. As a cause of this relationship she changes her personality when she begins to receive anonymous telefon calls.

Broadcast 6 December 1990, this episode concentrates on animal communication. In Kenya, Attenborough accompanies a tribesman who calls to a honeyguide, which in turn answers him and leads the pair to a bees nest. The tribesman extracts the honey, and some is left to reward the bird. African hunting dogs are shown hunting gazelles, of which the target is the individual that leaps lowest. Larks evade merlin by sending a similar message: by continuing to sing while being chased, it tells the pursuer that its prey is fit and therefore will be difficult to catch (see handicap principle). (In 80% of cases this turns out to be true.) Vervet monkeys cries are among the most complex.