Mister Monday is the first novel in the series The Keys to the Kingdom by Garth Nix. It follows Arthur Penhaligon, a twelve-year-old boy who discovers that he is the heir to an otherworldly House and must fulfil a mysterious Will in order to claim it from seven antagonistic Trustees. Plot Twelve-year-old Arthur Penhaligon is experiencing a severe asthma attack at school when two mysterious men, Mister Monday and his butler Sneezer, appear in front of him. Sneezer convinces Monday to give Arthur his Minute Key in order to fulfill Monday's directive from the Architect. Although Monday is skeptical, Sneezer argues that Arthur will die shortly and the Key will then be returned to Monday. However, Arthur is saved when school officials arrive with help. Sneezer and Monday disappear, leaving a small book in their place, which Arthur takes. Arthur spends a week in the hospital and is visited by his new friends Leaf and her brother Ed. Leaf confirms that she also saw Monday and Sneezer, and Ed adds that he saw dog-faced men digging up the school field looking for something. Arthur realizes that they are looking for his Key. Once back at home, Arthur uses the Key to open the book, The Compleat Atlas of the House and Immediate Environs, which describes the House and its environs. That night he is attacked by the dog-faced men that Ed saw, described as "Fetchers" by the Atlas. The Key protects Arthur by bringing his ceramic Komodo dragon to life to fend off the Fetchers. The next day at school, Arthur learns that Leaf and Ed have contracted a mysterious disease. More Fetchers attempt to pursue Arthur and he is also attacked by Monday's Noon, a more powerful creature. Arthur manages to evade them all, but his day is further interrupted when a medical team announces a city-wide quarantine as the mysterious disease spreads. Arthur realizes the Fetchers are spreading the disease and he decides to enter the House in hopes of finding a cure. With help of the Atlas, Arthur navigates his way through the House, which he discovers is a world unto itself, around which the Universe is organized, created by a divine being called "the Architect." The Architect went away and entrusted the seven Trustees known as "the Morrow Days" to fulfil her Will. Prior to the Architect's departure, she imprisoned her consort, the Old One, for