When the sun no longer rises, Princess Twilight Sparkle discovers that all the other alicorns have mysteriously disappeared and she is now the last one left in the world. After learning from a dragon that the mythical King Sombra may be responsible for their disappearances, she becomes determine to find out what happened to them. With great reluctance, she leaves her home of Equestria for the first time to venture out into the unknown world. Along the way, she befriends some humans while making enemies with others as she experiences things she never thought possible, and, along the way, risks losing everything, even her very identity.