The Mysterious Stranger is a novella by famed American author and satirist Mark Twain (1835-1910). He wrote it between 1897 and 1908, in the years leading up to his death, but left it unfinished. Most editions in circulation are the result of his literary executors and editors combining variations of Twain’s unfinished manuscripts. The novella is tonally and thematically different from many of Twain’s more popular works, including supernatural elements and grappling with questions of morality and religion. All versions include a character who is named either Satan or No. 44. The work has been adapted for film in 1982 and 2020 in the United States and in 1989 in the Soviet Union. A British opera based on the work appeared in 2014.

This guide uses the edition published by Merchant Books in 2018, which may vary from other versions of the text. Readers should check their edition of the book to ensure there are no significant discrepancies.

Plot Summary

The Mysterious Stranger takes place during the Middle Ages, and its narrator is a young boy named Theodor Fischer. He and his friends, Seppi and Nikolaus, live in the fictional Austrian town of Eseldorf, which is secluded and filled with devout townspeople. Theodor describes the adventures he and his friends have with a strange visitor.

One spring day, as the boys are playing in the woods, they meet a handsome teenage boy who is able to miraculously light their pipe by breathing on it. He reveals himself to be an angel named Satan and is the nephew of the devil. To prove this and gain their trust, he performs several magical acts, such as conjuring fruits and candy. The boys are delighted to have a heavenly new friend.

Eventually, Satan offers to help the boys create a clay castle, complete with living clay villagers, soldiers, and horses. However, when the clay men begin fighting amongst themselves and exhibit physical deformities, Satan destroys the village, sending it down a chasm to hell. The boys are horrified, but Satan dismisses their emotions, telling them that their lives are insignificant and that they can make more whenever they want. As he prepares to leave, the boys beg him to help Father Peter, a local priest who is experiencing financial difficulties. Satan disappears as Father Peter approaches and enchants the boys so that they are unable to disclose his true nature. He also instructs them to call him by the name Philip Traum when they see him around town.

Father Peter arrives, asking the boys to help him find his wallet. They quickly find it filled with gold coins. Theodor, confident that this must be Satan’s divine intervention, encourages Father Peter to keep it. However, his luck abruptly ends when his enemy, the town astrologer, accuses Father Peter of stealing the money. He is quickly arrested, leaving his family destitute. The boys quickly find that Satan’s intervention always includes unforeseen consequences. He gives Father Peter’s family a cat that is meant to bring money and fortune, but this leads the zealous townspeople to accuse the family of witchcraft.

Theodor grows concerned about the future of his family and friends and begs Satan to protect them. Satan obliges, saying he can change their predetermined path, which he calls a “career.” He redirects the careers of Nikolaus and a local girl named Lisa, promising that both of their lives will be improved as a result. However, Satan has a utilitarian view of what this improvement is; Nikolaus and Lisa are now both doomed to die in twelve days, after Nikolaus succumbs while attempting to save her from drowning. Satan explains that the alternative was him surviving but living the rest of his life in misery and pain. Theodor and Seppi helplessly watch Nikolaus creep slowly towards his death and try to comfort themselves knowing that he avoided a horrible fate. Satan alters Lisa’s mother’s career, claiming that it will relieve her of her suffering. However, he sentences her to burn at the stake after she publicly condemns God for allowing Lisa’s brutal drowning. Satan explains that he saved her decades of grief and mourning.

To show the boys flaws in human logic, Satan frequently takes them around the world, showing them different places and times. The common thread of these visits is displays of unspeakable human suffering. Theodor and Satan see a prison where a man is being tortured for blasphemy, people of all ages being worked to death on the factory line, and religion leading people to hysteria and social division. Satan attributes this to the failings and hypocrisy of the “Moral Sense,” the uniquely human ability to tell right from wrong. Satan believes humans apply it selfishly to justify their own actions while ignoring suffering. This—combined with other perceived failings, such as mortality—is what inspires his negative views on humanity. The visions Theodor sees constantly horrify him, as does Satan’s casual cruelty to others and his skewed moral compass.

Shortly after their journey, Father Peter’s trial begins. Theodor and Seppi are hopeful that he will be found innocent, but the astrologer is able to give a persuasive testimony. Just in time, Satan appears at the court and possesses Father Peter’s lawyer. As a result, the once anxious lawyer is able to effortlessly debunk the astrologer’s claim, decisively proving Father Peter’s innocence. However, as usual, Satan’s help comes at a price. While Theodor and Marget, Father Peter’s niece, were on their way to collect him from jail, Satan appeared in his cell and told him the court ruled against him. When the duo arrives at Father Peter’s cell, they are horrified to find him in the throes of insanity, convinced he is an emperor. Satan tells Theodor that Father Peter is only able to attain true happiness in this state, as the insane are unable to perceive the horrors of the world.

After a particularly long absence, Satan appears to Theodor and tells him that while he enjoyed his companionship, this will be his final visit. When Theodor says he hopes to meet him in another life, Satan tells him that this is Theodor’s only life, revealing that “Life itself is only a vision, a dream” (103). He says that his eventual disappearance will be a sign that Theodor understands and accepts this reality. As Satan vanishes, Theodor intuitively knows that his claim is true.