He is a serial killer who attempts to kill his brother and take over his fortune, but has randomly killed more people in an alphabetical order, both in the victims' name and their hometown. He also challenged Poirot for the case, because the latter was a celebrated foreign detective, before framing someone else.
In the Agatha Christie's Poirot, Franklin was portrayed by Donald Douglas, and in the 2018 BBC miniseries, he was portrayed by Andrew Buchan.
Plot of The ABC Murders
After a meeting with the third victim's widow, Lady Clarke, Poirot realises one commonality at each of the three murders: a man selling silk stockings appeared the day of the murder. He sold a pair to Mrs. Ascher and to Mrs. Barnard, while being sent away from the Clarke home. A.B.C. sends his next letter, directing everybody to Doncaster. As the St. Leger horse race will take place that day, Poirot hopes to find him on the race course. But A. B. C. strikes in a cinema hall instead, killing George Earlsfield, instead of Roger Emmanuel Downes, a logical victim sitting only two seats away. However, Cust, about whom neither the Legion nor Poirot knows, slips out of the cinema hall unnoticed, after suffering a blackout. Cust, who has no idea of the happenings, finds the murder weapon in his pocket, blood on his sleeve, and realises the implications.
Tom Hartigan tips off Crome, while Lily tips off Cust, who tries to flee, but collapses at the Andover police station. When taken into custody, he believes he must be guilty. The search of his rooms finds silk stockings, lists of clients, the fine paper of A.B.C.'s letters to Poirot, an unopened box of ABC railway guides, and in the hall, the still-bloody knife used in the last murder. The police find that Cust was never hired by the stocking firm and the letters were typed on the typewriter he claims was given to him by the firm. Poirot meets Cust, but doubts his guilt after hearing Cust's full story; Cust has a solid alibi for the Bexhill murder and has no memory of any murder. Poirot calls a Legion meeting. He categorically proves that Cust is not the murderer. Early on, in discussing the Churston letter, Hastings remarked that the letter was meant to go astray. Poirot realises this simple solution is the correct one. The murderer wanted no chance of the police interrupting that murder. Poirot reveals that A.B.C. is in fact Franklin Clarke.
Franklin feared that after Lady Clarke's imminent death, Carmichael would marry Thora Grey. This would mean that the estate which Franklin stood to gain would go to Thora and any children she might have with Carmichael. Franklin decided to kill his brother while Lady Clarke is alive and make it look like a serial killing to throw off suspicion. Franklin met Cust in a chance encounter in a bar, thus giving him the idea of A.B.C. He planned and executed everything so that Cust would be framed, having served as his stalking horse.
Franklin laughs off Poirot's claims, but panics when Poirot states that his fingerprint was found on Cust's typewriter key, and that Franklin had been recognised by Milly Higley in the company of Betty Barnard, the second victim. Franklin tries to shoot himself using his gun, but Poirot has already had the gun emptied with help of a pickpocket. Franklin was arrested following that.
In the Adaptations
Agatha Christie's Poirot
In Agatha Christie's Poirot, Franklin's role remained relatively same to that of the novel, but he chose to escape instead of committing suicide when Poirot revealed him to be the murderer. However, he was soon subdued and arrested by the police.
In the 2018 BBC miniseries adaptation, the motive of Franklin is revealed to be a lot more unhinged and vile than in the novel. While Franklin of the novel was motivated by greed only, the miniseries version of the character starts to enjoy his role as the ABC Killer so much that he continues murdering people to continue the "game" with Poirot. He only frames Cust because the latter's illness would prevent him from continue traveling, which implies that, unlike the novel, Franklin really was willing to go through the entire alphabet.
However, this version of Franklin has some decent respect towards Poirot, particularly in the ending. He is also more composed when Poirot exposed him, revealing that he was trying to restore the great detective's publicity through the case and prove that he was a worthy opponent.
- Alice Ascher (in Andover)
- Betty Barnard (in Bexhill)
- Sir Carmichael Clarke (in Churston)
- George Earlsfield (in Doncaster)
- Alexander Bonaparte Cust
- Franklin Clarke is considered as one of the most evil villains in Hercule Poirot series. He is also considered to be one of the darkest killers in Agatha Christie's works alongside Nevile Strange, Stephen Norton, Michael Garfield, Josephine Leonides, Emily Caroline Brent, Anthony James Marston, Yahmose and Dr. James Kennedy.
- Coincidentally, his actor in TV Series has an alliterative name, Donald Douglas, befitting the story's theme.