The Secret Families — John E. Gardner

The final volume in The Secret Generations Trilogy

It is December 1964, and Caspar Railton is dead. But after a lifetime of distinguished work in the British Secret Intelligence Service, it now appears that Caspar was a traitor. Sine his death, witnesses and documents have surfaced attesting to his treacherous past, and both the Railton clan and the Farthings -- the American family joined to the Railtons through marriage and a shared commitment to espionage -- become suspect as well.