The same night, at the Centaur Club, Blake explains to Professor Philip Mortimer the difficulty of dismantling such a network where are agents unknown even among themselves.

Entering a home in the English countryside, Blake faces his old enemy Colonel Olrik and his man, Jack, killing Jennings.

In Seanberry, Virginia reveals to Mortimer that she is a sleeper agent (aka 'cousin') in the service of Blake and that the betrayal of the latter is just a covert operation to infiltrate the spy network.

But in the early morning, things get complicated when the Home Secretary, the only person of significance knowing of the operation, is the victim of a car "accident".

In London, Honeychurch  – who turns out also to be part of the operation  – is caught red-handed by the Under-Secretary of State for the Home Office, Harold Doyle-Smith, in person.

Blake tells him that Olrik's plan is to kidnap the brightest physicists of the Kingdom and make them work on behalf of a foreign power.

Mortimer, surrounded, jumps into the water from the top of a cliff, while Blake gets in a car, of which the occupant turns out be the Under-Secretary of State Harold Doyle-Smith.

When Blake sees the six fingered hand of industrialist Adrian Deloraine, he recalls Fielding's warning and understands that the Under-Secretary of State is the Mole.