Jul 24, 2014 Updated: 6:46 AM
A modern, edgy drama full to the brim with passion, politics and peril. MI-5 leads us into the dangerous world of Britain's top-secret security agency, and into the lives of people who must lie, and sometimes die, for a living.
VISIT THE BBC's MI-5 WEB SITE
Martin and Louisa are at their wits' end due to their constantly wailing baby; Aunt Ruth deals with an intruder on the farm; Martin treats a woman who believes her son is poisoning her.
Find out about upcoming shows, special events, and discounts.