Episode 5 of 5: Seals
Grey seals are Britain's largest mammal, yet still remain a mystery.
Mary Colwell Meets Sue Sayer on a windy cliff in Cornwall to view the animals she loves so much.
Sue now spends all her time discovering their lives. She used to be a teacher, but as her passion for seals grew she found herself spending more and more time with seals.
Sue eventually gave up her paid job and became a champion of seals.