sentences:  They are Sir Edward Leithen, lawyer, Conservative Member of Parliament (MP), and ex-Attorney General; John Palliser-Yeates, banker and sportsman; and Charles, Earl of Lamancha, former adventurer and present Conservative Cabinet Minister.Under the collective name of "John Macnab", they set up in the Highland home of Sir Archie Roylance, a disabled war hero who wishes to be a Conservative MP.They issue a challenge to three of Roylance's neighbours