For those following the series' complex web of espionage, here is how the team navigates the crisis:
The episode focuses on the fragile state of the British economy as a high-stakes financial threat emerges. Ros Myers goes undercover to expose a dangerous international financier, Alexis Meynell, who plans to bankrupt Britain.
Takes the central role, balancing the physical danger of her undercover identity with the intellectual rigour needed to take down a financial genius .
While "On the Brink" is the specific title for this episode, the phrase is common in recent media guides: