Tensions with Russia escalate, and an imaginary week in the near future takes a turn for the unexpected. The Prime Minister calls an emergency Cobra meeting.-Russia knows our weaknesses. But do you? A major five-part series from Sky News and Tortoise which imagines how a Russian attack on the UK could play out – and invites real-life former ministers, military chiefs and other experts to figure out how to defend the country. Written and presented by Sky News' security and defence editor, Deborah Haynes.