.Hack//Infection is the first of a series of four games, titled .hack//Infection, .hack//Mutation, .hack//Outbreak, and .hack//Quarantine, features a "game within a game"; a fictional massively multiplayer online role-playing game (MMORPG) called The World which does not require the player to connect to the Internet. Players may transfer their characters and data between games in the series. Each game comes with an extra DVD containing an episode of .hack//Liminality, the accompanying original video animation series which details fictional events that occur concurrently with the games. The games are part of a multimedia franchise called Project .hack which explores the mysterious origins of The World. Set after the events of the anime series .hack//Sign, the games focus on a player named Kite and his quest to discover why some users have become comatose as a result of playing The World. The search evolves into a deeper investigation of The World and its effects on the stability of the Internet.
The game opens with an excerpt from Emma Wielant's Epitaph of Twilight and is followed by a name input screen. This is where the user name and the character name are entered. For consistency's sake, the main character will be referred to as Kite, the default name for the character. Kite has been invited by his friend, Yasuhiko, to play The World. While Yasuhiko, known as the legendary player Orca, shows Kite the ropes, the two encounter Aura. Just as Aura is about to entrust Orca with the Book of Twilight, Skeith attacks. Orca tries to defend himself and Kite but is no match for Skeith and ends up being Data Drained. Just as Skeith is about to do the same to Kite, someone distracts Skeith and transports Kite to Net Slum. There, the Book of Twilight is added to his inventory. It was at this time that The World's servers crashed.
