Nick Buckley

"You silly little man, you don't know anything. You're all... so... stupid! Let me get my watch."

- Nick revealing her sinister true colors

Magdala “Nick” Buckley is the main antagonist of Dame Agatha Christie's 1932 Hercule Poirot novel Peril of the End House, and its adaptations.

She was portrayed by the late Olga Edwardes in the novel's 1940 stage adaptation, and by Polly Walker in its 1990 adaptation from Agatha Christie's Poirot, with the latter later portrayed Peggy Sykes in Pennyworth.

Overview
Originally introduced as the novel's triangonist, she is a young woman living at End House, near St. Loo. After some encountering, Hercule Poirot believed someone is trying to kill her. However, it was revealed that Nick was the mastermind behind most of the events in the story, including the murder of her cousin with the same name, Magdala " Maggie " Buckley, in order to obtain the fortune of Maggie's fiance, the late Michael Seton.

While initially seen as a cheery, clumsy and carless woman, Nick's true colors was soon revealed to be nothing but an utterly hateful, manipulative, murderous and sinister woman, with her even angrily insulting Poirot and everyone in the scene once she was exposed as the culprit.

History
Magdala "Nick" Buckley was the owner of the End House, as well as the friend of Navy Commander George Challenger. Her cousin, Maggie, who shared the same first name  Magdala  with her, was engaged to Michael Seton, a renowned pilot, prior to his disappearance. Soon, after the news of Michael Seton's death emerged, Nick plotted her cousin's murder while pretending herself to be Michael's fiancee instead of Maggie.

After meeting with Poirot, Nick had staged that she had met several seemingly accidents in order to draw Poirot's attention. Later at the night, during the party, Nick killed Maggie after making Maggie to wear her shawl, giving a false information that the killer was trying to kill Nick, but mistook Maggie as their target instead. When Poirot found Maggie's corpse, he fell into guilt for not taking the duty seriously.

Later, with the news of Michael Seton's death had been reported, Poirot discovered that the death of Michael was the news Nick had received in her call. In the meantime, Nick found Poirot and (falsely) "revealed" she had been engaged with Michael Seton, whose fortune would be inherited by his fiancee. Poirot and Hastings soon found love letters (seemly) between Nick and Michael, who adressed her as " Magdala ". Nick was later poisoned by a chocolate that contained coccaine, sent under the name of Poirot, but it was actually sent by Freddie Rice, a close friend of Nick and a drug addict who was exploited by her abusive husband. However, it was actually Nick who manipulated Freddie into sending the chocolate, where she injected it with a surmountable amount of coccaine and faked her condition.

Nevertheless, while investigating the Crofts who became suspicious, Poirot could not find any trace of Michael comforting Nick about her recent surgery. His later conversation with Hastings around English nicknames cemented his suspicion further, since Hastings nonchalantly mentioned that the name Magdala could have many nicknames including  Maggie . As a result, Poirot deduced that the murder was actually aimed at Maggie all along, and it was Maggie who was engaged to Michael Seton, not Nick.

Poirot later made Nick to participate in a ruse to expose the Crofts, who forged the will of Michael and sent it to Charles Vyse. While they were not responsible for Maggie's murder, Inspector Japp revealed them to be a pair of notorious forgers and arrested them. After dealing with the arrest of the Crofts and a failed ambush aimed to Freddie by her dying husband, Poirot revealed to everyone that Nick was the murderer and made Japp arrested her. Now exposed, Nick angrily insulted everyone and revealed her sinister true nature, before taking away a "souvenir" - Freddie's wristwatch - and walked away with Japp.

In the epoligue, Poirot revealed that Freddie's wristwatch contained a lethal amound of coccaine, knowing that Nick would soon commit suicide with it to escape the gallows. He also revealed the identity of supplier of any coccaine in Nick and Freddie's possession. The said coccaine supplier was George Challenger, who was involved in a drug trafficking.

Trivia

 * Nick's case had deconstructed a character archetype from traditional detective fictions surrounding the initial victim and the character who asked the detective for help, who were always not guilty. Turned out, Nick was the culprit of Magdala's murder herself instead of a target of the culprit, right after she helped Poirot to expose another crime (for her self-serving arrangement, obviously).