An ailing Poirot returns to Styles with Hastings nearly three decades after solving their first mystery together there in order to prevent an unscrupulous and ingenious serial killer from claiming more victims.

Lucy Crale hires Poirot to solve the murder of her father sixteen years before, and Poirot finds a number of possible suspects who are still alive.

A wealthy British heiress honeymooning on a Nile cruise ship is stalked by a former friend, whose boyfriend she had stolen before making him her new husband.

Poirot investigates the murder of a shady American businessman stabbed in his compartment on the Orient Express when it is blocked by a blizzard in Croatia.

Four clocks surround an unidentified corpse in a blind woman's house, and a young typist is summoned to the crime scene. However, Poirot is convinced that the complicated setup is merely hiding a simpler solution.

In an effort to recover his confidence after a rare professional failure, Poirot sets off for the Swiss Alps in pursuit of a missing maid.

Poirot investigates a strange and gruesome murder of an elderly psychiatrist. Ariadne Oliver is pressed to try and uncover the truth behind two decade-old deaths. They soon find out that their separate investigations are linked and work together to try and solve the mystery.

Lady Edgware has a dilemma in that her husband has consistently refused to give her a divorce. She asks Hercule Poirot to visit the man and see if there is any possibility of convincing him. When Lord Edgware is found dead, there is no great surprise, but there are a good number of suspects.

Poirot finds a connection between a recent murder and a revolution in the Middle Eastern kingdom of Ramat.

Young Elinor Carlisle, engaged to marry the dashing Roddy Winter, finds herself charged with the fatal poisoning of Mary Gerrard, her rival in love. Poirot has the job of saving Elinor, but the evidence against her is overwhelming.

Beside the bodies of three murder victims lies a copy of the ABC Railway Guide.

Hercule Poirot finds himself investigating the murder of his dinner host, Mr. Shaitana, who was stabbed in the heart while his guests played bridge.

Poirot and Hastings are at Lake Windermere for an attempt on the world speed-boat record. An elderly widow is hurt by falling down stairs, then later killed by poisoning with phosphorus.

Recovering from the horrors of World War I, British Army officer Arthur Hastings hopes to find peace and quiet at a country manor in the English countryside. But when the matriarch dies during the night from strychnine poisoning, Hastings enlists the help of an old friend staying nearby with other war refugees to help solve the murder: former Belgian police detective Hercule Poirot.

With the world on the brink of WWII, there is more political turmoil when it appears that the famous Peace Party is in fact a cover for the Big Four.

Ariadne Oliver is asked to devise a murder hunt for a Devon fête, but her sense of foreboding summons Poirot to the scene. Her fears are realized when, during the fête, the girl playing her murder victim winds up well and truly murdered.

Three single girls share a London flat. The first works as a secretary; the second is an artist; the third, who comes to Poirot for help, disappears believing she is a murderer.

Hercule Poirot's solicitor, Gilbert Entwhistle, asks Poirot to help solve a riddle and a murder.

Poirot is spending a week-end with the Angkatells, at their country house called The Hollow.

After collapsing with heart problems, Hercule Poirot visits a seaside health farm on Burgh Island. While there, the flirtatious heiress Arlena Stewart is found strangled on a secluded beach.

While accompanying his friend Hastings to a dig in Iraq, Hercule Poirot becomes involved in the murder of an archaeologist's wife.

Country squire Marcus Waverly calls on Poirot for help in dealing with kidnap threats against his son. Hastings is appalled by the thought of someone going around kidnapping children and it becomes a race against time to find the identity of the mystery letter writer.

Marie Marvelle, a Belgian film star, receives threatening letters from a chinaman which demand her famous diamond, the Western Star. Marie visits her old friend Hercule Poirot in London, seeking his help, and Poirot tackles the case with relish.

At a London restaurant where he often eats, Poirot notices that another regular customer has diverted from his usual meal. As old Anthony Gascoigne lies dying in Brighton, his estranged twin brother, Henry, falls to his death. A tragic accident, or murder? Poirot begins to see connections and decides the answer to the mystery lies in a blackberry pie.

Hercule Poirot accompanies his friend Captain Hastings on a weekend shooting party at the home of Harrington Pace, but he isn't having a very good time. He comes down with the flu and takes to his bed but when Pace is shot dead in his study, he rises to the occasion to assist Inspector Japp in solving the case.

Poirot is summoned to Marsdon by the owner of a country inn there to solve a murder. But the inn-keeper is a would-be thriller writer, and to Poirot's dismay the murder turns out to be fictional. Thankfully, though, there is soon a real (if seemingly supernatural) murder at the big house. Things get even more interesting when a young wife claims that a tree in her garden is haunted by a laughing ghost, and there are also signs of black magic from East Africa. Poirot lays a clever ambush to smoke out the killer,confident that he or she will turn out to be human.

An Australian shipping tycoon wants Poirot to check out his daughter's suitors. Then the young lady takes a trip on the Plymouth Express, and Poirot finds himself investigating a jewel theft on the train.

A wealthy industrialist is found dead in his study. Is his death related to a discovery made at his chemical factory? And is his wife all she seems?

Lovely young actress Valerie St Clair, engaged to marry Prince Paul of Maurania, is the only witness to the murder of Henry Reedburn, a shady and overbearing producer. Prince Paul appeals to Poirot to save Valerie from police suspicion, and the great detective finds he has a conundrum to ponder on, 'When is a murder not a murder?'

Poirot is drawn into the underworld of London's Little Italy when Captain Hastings looks for a new car, but instead finds murder.

Within hours of the Bonfire Night fireworks beginning Poirot finds himself investigating a violent death in Hastings' mews garage.

Poirot tells a surprised Hastings he's decided to retire and suggests they take a holiday in the Lake District. On the way, Hastings befriends a young woman who is missing a collection of valuable miniatures. The case involves a famous writer and a beautiful woman in a sports car, and to the relief of Hastings Poirot's thoughts of retirement soon seem far away.

Poirot travels to Cornwall, summoned by a Mrs Pengelley, who suspects her dentist husband is poisoning her because he's fallen in love with his young assistant. Unhappily, Poirot finds Mrs Pengelley dead on his arrival, so he sets out to catch her killer.

Poirot is called in to help a woman who lives in fear of her husband, and he is invited to a dinner party which goes horribly wrong.

Lord Mayfield, an aircraft manufacturer, tries to trap a spy at his country house, but his plan goes terribly wrong. Lady Mayfield sends for Poirot, who tells a few home truths.

Japp (who is really worried that failure could cost him his job) seeks Poirot's help in investigating a series of jewel thefts, and two remarkable things happen. Poirot falls in love (with the beautiful and clever Countess Vera Rossakoff) and he also meets a criminal intellect which he finds worthy of him. As the countess is his main suspect, Poirot spends most of his time with her - which for once leaves Hastings and Miss Lemon to do most of the actual detective work. In the end, this case may have to be put down as the one that got away.

Hastings and Poirot are playing Monopoly when they are interrupted by Lord Pearson, the elegant Chairman of the London and Shanghai Bank. The banker asks them to investigate the disappearance of a Mr Ling - a highly-valued customer who before he went missing had arranged to sell Lord Pearson a map showing the location of a long-lost silver mine. Ling is found murdered, a young stockbroker is implicated, and Poirot has to untangle a complicated plot.

Poirot is called in when the British Prime Minister and his secretary are kidnapped in France on their way to a League of Nations conference - and he is given just a day and a half to solve the case.

A glamorous nightclub singer turned spy has stolen the US Navy's plans for a new submarine, and an FBI agent called Burt is in London to catch her. Burt dismisses Poirot as a gumshoe, and Poirot is likewise not impressed by the self-important G-man. Poirot is drawn into the case when it appears that the submarine plans will fall into the hands of the Fascist government in Italy unless they are recovered. When Poirot meets a young couple who've got an amazing bargain on a prime apartment, he sees a connection with the spy case.

Poirot prepares to spend a quiet Christmas on his own with a box of chocolates, but he has to give up his plans when the British government asks for his urgent help. Prince Farouk, a young member of the Egyptian royal family visiting London, has lost a famous ruby, and this is deemed to be a matter of national security.

Poirot is on holiday at the Palace Hotel, Rhodes, when an Englishwoman, Mrs Valentine Chantry, is poisoned. Poirot unravels several complicated relationships between those staying at the Palace Hotel.

Poirot calls to see the veiled lady of the title (Lady Millicent Castle-Vaughn) at her London hotel. Lady Millicent is about to be married, but a mean blackmailer called Lavington has got hold of a love letter she wrote years before to another man. Lavington wants twenty thousand pounds, and Poirot makes up his mind to recover the letter himself, even if it means impersonating a Swiss locksmith.