Illustrations from 1975, 1978 in faint and blotchy different unattributed artists' styles date two stories from 1950, 1930. The former add more mood - pensive, apprehensive - to complex woven tales first whodunit, second espionage almost sci-fi, both with big cast of soap opera interactions, typical Agatha chitchat.
"Crooked House" like nursery rhyme, houses family, not dishonest, but overly dependent on the intense personality of wheeler-dealer beloved Leonides patriarch. Grand-daughter Sophia at 22 was proposed to at the end of WW2 by narrator Charles, son of a Scotland Yard Inspector Taverner "Old Man". Two years later, Sophia refuses to marry until they uncover the murderer of Aristide 88. His insulin injection bottle was filled with his eyedrop eserine solution; he warned the family himself of the danger. Youngest grand-daughter Josephine says she knows the murderer, is attacked, and her cocoa poisons Nanny. Charles is the inside investigator.
"Passenger to Frankfurt" is the stranger, with hint of resemblance to long-gone sister, who convinces bored diplomat Sir Stafford Nye, to lend his passport and enveloping hooded distinctive cloak, that she might transit safely on to England. While he sleeps, drugged willingly by a Mickey Finn in his beer, announcements broadcast for Miss Daphne Theodofanous, passenger to Geneva flight diverted to Athens and danger by fog. At a London embassy dinner, she is exotic Countess Renata Zerkowski. To espionage master Lord Altamount, she is Uncle Ned's cleaner-upper Mary Ann. She guides Staffy through Bavarian Youth Music Festival, to elephantine Gräfin (Countess) Charlotte von Waldsausen, who was at Swiss school with his great-aunt Lady Matilda Cleckheaton née Baldwen-White. The obese villain's charismatic protegé, excellent singer and orator, "young Sigfried" rouses youth worldwide to destructive riots, returning Nazi Aryan genocide in a worldwide conspiracy of drugs, weapons, science, and moles.