Dec 18, 2013 Updated: 10:06 PM
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
In the series finale, Harry's team frees him from CIA custody; and Elena claims to have knowledge of an imminent attack on the U.K., which may be in the form of a passenger jet approaching London.
Find out about upcoming shows, special events, and discounts.