.hack//Quarantine
.hack//Quarantine is the fourth game in a series of four games titled .hack//Infection, .hack//Mutation, .hack//Outbreak and .hack//Quarantine. It is a "game within a game," a fictional massively multiplayer online role-playing game (MMORPG) called The World that does not require players to be connected to the Internet. Players can transfer their characters and data between games in the series. Each game comes with a DVD containing an episode of .hack//Liminality, the accompanying original video animation series that describes fictional events that take place simultaneously with the games. The games are part of a multimedia series called Project .hack that explores the mysterious origins of The World. The games, set after the events of the anime series .hack//Sign, center on a player named Kite who wants to find out why some users have fallen into comas as a result of playing The World. The quest evolves into a deeper investigation of The World and its impact on the stability of the Internet.
Story
Fresh after the victory against Gorre, Kite meets Elk, who is still looking for Mia. Kite has no information, so Elk continues his search. Kite then goes to the newly opened Ω-server to discuss the next step, but the server crashes, forcing Helba to send everyone to her mirror server. Helba's server has all the same features, except the server looks like Net Slum. Now that they are relatively safe, Helba says that the wave is still on the move and that she will work on a vaccine to defeat it. Lios orders Kite to measure the data fluctuations by going to the Ω Bigoted Snowflake's Capsule. Shortly after getting the data for Lios, it is reported that there has been a power outage at Nizato University Hospital, where Yasuhiko is staying. Kite doesn't have much time left. Fortunately, he receives another clue from Spiritas, a resident of Netzslum, who tells him that Harald has something to do with the Doom Castle of Σ Screaming Wind Sand. At the bottom is another room, this time with a lone tree in the sunset and another epitaph fragment.