You'll probably know Jon Richardson from 8 Out of 10 Cats Does Countdown but the comedian is out on his own in this documentary tonight where he is sent on a mission by his wife - fellow comedian and worrier Lucy Beaumont - to investigate whether the things they most fear will result in their deaths. He meets a family in Dorset selling fresh air in jars for £80 to combat lethal air pollution, spends a night in the woods to learn how to protect his loved ones in the event of terrorists setting off a dirty bomb, and encounters a man so committed to making himself invincible he tests a supposedly indestructible suit by strapping himself to a van and driving through a brick wall.