This collection starts off with "Elephants Can Remember." In this mystery, recurring character Ariadne Oliver (Zoe Wanamaker) is confronted by a woman at one of her book signings. Apparently, Mrs. Burton-Cox (Greta Scacchi) is the soon-to-be mother-in-law of Oliver's god-daughter, and Mrs. Burton-Cox has asked Ariadne to uncover some of the young Celia Ravenscroft's (Vanessa Kirby) past, particularly where the girl's dead parents are concerned.
Ariadne goes to Poirot asking for advice, but Hercule is preoccupied by another case. Poirot has been called into a local asylum to look into the murder of the institute's Director. It becomes quickly apparent that the prime suspect in the case is the victim's son, Doctor Willoughby (Iain Glen, Game of Thrones).
At first, Poirot is frustrated by Ariadne's case, as the death of a married couple about a decade in the past doesn't seem quite as urgent as his current task. Imagine his surprise when Ariadne's investigations starts to show connections with his own case. Now Poirot will work with the murder mystery writer to solve both the deaths of the Ravenscrofts and of the recently deceased doctor.
In the collection's next episode, "The Big Four," the world is on the brink of a second world war. The episode starts with Captain Hastings (Hugh Fraser), Miss Lemon (Pauline Moran) and the now Assistant Commissioner Japp (Philip Jackson) getting together at Poirot's funeral where they talk about the case that Hercule and Japp were working together, and the events that led to Poirot's death.
This mystery starts when Poirot attended a high-society gathering put on by The Peace Party, a pacifist group hoping to foster understanding. It just so happens that Japp in in charge of the party's security, though his own position at the event is more of a political one than actually enforcing security. When a grand master chess player dies in front of everyone, Poirot's investigation begins and he starts to learn of an apparent group of individuals that supposedly control the world and is guiding it to the upcoming war.
Poirot's clues lead him to uncover each of the members of The Big Four, but only just in time to discover them murdered, but not all of the pieces are adding up and Poirot starts to learn that not everything is as it appears. Unfortunately for Poirot, this investigation appears to lead to his death, or at least his funeral.
In "Dead Man's Folly," Ariadne returns as she is asked to put on a murder hunt. While Ariadne crafts a detailed mystery for the guests to uncover, she has a sense of foreboding that causes her to invite Poirot to the event in the hopes that he will soothe her fears. The actress playing the murder victim ends up actually being murdered and now Poirot and Ariadne must work through her own case to determine if the script she wrote has been influenced by the actual murder in order to set up the perfect case.
The series' second to last mystery, "The Labours of Hercules," starts off with Poirot failing to capture an art thief and the result is a death that he feels is on his conscience. After several months of reflection, Poirot takes on a new case that leads him to the Swiss Alps. While snowed in, he not only finds more mysteries than he expected, but also an old acquaintance in the Countess Vera Rossakoff (Orla Brady). A former thief in her own right, Rossakoff claims to have left a life of crime some time ago, and her daughter, Alice Cunningham (Eleanor Tomlinson, The White Queen) has become a thorough researcher of criminology and is especially interested in Poirot himself.
This is actually an unusual adaptation of Agatha Christie's work. The original book was a collection of twelve short stories that Poirot recounts to the other guests at the Swiss hotel. In the book, each story is tied to one of the twelve mythical labors of Hercules. In this episode, several of the mysteries happen concurrently at the hotel itself and the "labors" themselves are portrayed as stolen paintings.
Agatha Christie's Poirot: Series 13 wraps up with a mystery that I have been anxiously waiting for since I first heard it was being produced. "Curtain: Poirot's Last Case" follows the Belgian detective during the last few weeks of his life. Confined to a wheelchair and debilitated by heart problems, Poirot has returned to the scene of the first murder he and Hastings worked together. Hastings himself returns to be with Poirot at the end of his life, not only to visit with his old friend, but to also visit with his daughter who works for a scientist whose wife is ill and being cared for at the same estate.
As Poirot and Hastings talk, Hastings gets the feeling that Poirot chose this location for more than just nostalgic reasons. Poirot claims that there will be another murder here soon, but he does not know who the murderer or victim will be. He asks Hastings to be his eyes and ears around the estate to help Poirot identify the impending threats. Murder does seem to be in the air though, as one woman is apparently accidentally shot, and another is poisoned to death, and even Hastings himself seems to have it out for the man his daughter appears to be having an affair with. With so many stray plot points, it seems like Poirot’s last case is nothing but a series of red herrings, but everything ties together beautifully. I was especially impressed with Suchet’s portrayal of the ill and failing Poirot whose body might be broken, but whose mind was as sharp as ever.
Agatha Christie's Poirot: Series 13 has two special features. One is a photo gallery, while the other is a 19 minute long Q&A with Suchet. Poirot has been a great series that has provided intriguing mystery after mystery. While not all adaptations of Agatha Christie’s works were followed to the letter, they were at least enjoyable to watch and try to solve alongside Poirot. As a final season to this long-running show, Series 13 ends with some of the best episodes I’ve seen in a while. If you are even a casual follower of this series, then you will have to get this last collection.