- "Travelers take this to heart, it is always darkest before the dawn..."
- — Harald —
.hack//QUARANTINE (.hack//絶対包囲 Vol.4) (Japanese title: Absolute Encirclement) is the fourth and final volume of the .hack//Games saga.
Fresh off the victory against Gorre, Kite finds Elk still searching for Mia. Kite has no information, so Elk continues his search. Kite then moves on to the newly opened Ω Server to discuss the next move, but the server crashes, forcing Helba to connect everyone to her mirror server. Helba's server has all the same functions, except the server looks like Net Slum. Now that they are relatively safe, Helba says that the Wave is still moving and that she will work on a vaccine to defeat it. Lios then orders Kite to measure data fluctuations by going to Ω Bigoted Snowflake's Capsule.
Shortly after getting the data for Lios, it is reported that the Nizato University Hospital, the place Yasuhiko is being hospitalized in, suffered a blackout. Kite does not have much time left. Luckily, he gets another clue from Net Slum resident Spiritas, who tells him of Harald having something to do with Σ Screaming Wind Sand's Fate Castle. At the bottom is yet another room, this time with a lone tree at sunset and another Epitaph fragment.
Upon returning, Kite meets up with Elk again. Kite suggests that Elk join him, as they are likely to meet up with Mia along his quest. After helping Piros out yet again, Kite is ordered to meet the Wave at Ω Cruel Vindictive Scars. Nothing is there, however, and Lios reports that the Wave suddenly started heading to Σ Graceful Tempting Fallen Angel. Kite rushes there and finds Mia and Elk at the bottom of the dungeon. Shockingly, Mia says that she has no memories outside of The World and transforms into the 6th Phase, Macha. Kite has no choice but to drain and destroy Macha. Upon the Phase's destruction, Mia's data disperses into nothingness. Elk blames Kite for killing Mia and runs off as Lios tells Kite that the wave is returning to Ω Cruel Vindictive Scars.
In the dungeon, Lios reports that Elk has run away from his post with the vaccine. At the bottom, Cubia once again appears. Lios orders Kite to abort the mission, as the Wave has absorbed the special vaccine and created an antibody, wiping out Lios's entire team. However, Kite returns Aura's final segment to her and the Wave stops dead in its tracks, allowing Kite to continue and fight Cubia. Kite succeeds in repelling Cubia, who has grown even stronger, and is told that the Wave has started moving again.
At the Ω Server, the group has another meeting. Helba has created an improved vaccine that should still work against the Wave. To replace Lios's team, Helba gathers every person on Kite's friend list, including Mistral, who has decided to help out for the final battle. Anyone not fighting in Kite's party is given a vaccine and assigned a post to lead the Wave to Ω Cruel Vindictive Scars. The plan is named by Kite "Operation Orca." The operation succeeds as planned and the 7th Phase, Tarvos, appears in the dungeon. Kite defeats the Phase and prepares for the final battle.
Before the final battle, Kite searches out the creator of the game, Harald Hoerwick, who is located in Δ Reincarnated Purgatorial Altar. The dungeon proves to be larger than any encountered before and is filled with Data Bugs. At the bottom they find a large stone in the center of another white room. There is only a message from Harald. "The passage of time is irreversible. Birth or Death. Only these two possiblities exist. Traveler, take this to heart. It is darkest before the dawn." Aura appears, beseeching Kite not to fight Cubia, as Cubia is the shadow of the Bracelet and cannot be defeated so long as it exists. But Kite is determined to end things here and now.
Cubia proves to have grown a great deal more powerful, and it refuses to run away. After bringing its HP down to 0, Cubia merely resurrects itself. It seems impossible to defeat it. Kite then recalls that Cubia is the shadow of the Bracelet and orders BlackRose to destroy the bracelet. Despite her initial objection, she does so. As the bracelet is destroyed, Cubia also disappears into nothingness.
At the Ω Server, Kite reveals that they are without their greatest weapon, the Twilight Bracelet, but the enemy has also lost Cubia. Left without much time to plan, the Wave goes on the offensive and the final Phase, Corbenik, appears in front of them. The party seems to do well against it, defeating its first form and dealing considerable damage to its second. However, Corbenik puts up an indestrucbible barrier and no attacks do any damage to it. Just as it seems they have no chance to succeed, the spirits of all the coma victims, including Orca, Sieg, Sora, and Kazu, appear and attack Corbenik, weakening its shield, allowing Kite to strike the final blow and destroy it. They don't have much time to celebrate however, as the will of The World, Morganna, fuses with Corbenik and begins the attack anew.During the battle, the Ω Server starts to break down again. Just as it is on the verge of destruction, the battle is mysteriously moved to yet another mirror server (as a result of Junichiro Tokuoka and Mai Minase's efforts, as shown in the final episode of Liminality). With no more threat of a server breakdown, Kite's party continues the battle. Just as it seems Morganna is defeated, she pulls off her trump card: Drain Heart. Everyone is drained around him, and just as he is targeted, Elk makes an appearance and sacrifices himself to save Kite, asking forgiveness for what he did. Kite, angered at the sight and burning with the desire to save Orca, charges recklessly at Morganna, dodging her attacks. Just as he is about to strike, Aura appears in front of him and takes the hit. This occurs because, in order for her to become complete, it was necessary for Aura to understand the concept of self-sacrifice. As she dies, Aura also destroys Morganna and The World then begins to normalize. Everything has returned to what it should be, the coma victims reawaken, and the corruption is gone.
Some time later, the reborn Aura sends an e-mail to Kite and grants him the Book of Twilight ~ Daybreak. The bracelet and its power is restored to him, and he vows to use its power wisely. Shortly afterwards, he reads a BBS post about a mysterious cat player.
In Quarantine's epilogue, Kite receives an e-mail from Aura urging him to, "prevent the same mistake from happening again." He also receives a second e-mail telling him to go back to Bursting Passed Over Aqua Field. Elk receives the same e-mail and the two travel to the dungeon at Ω Hidden Darkside Holy Ground. There, they encounter Macha in cat form, whom Elk immediately recognizes as Mia. Together, the two fight through a perilous fifteen-floor dungeon packed with Data Bugs and eventually meet with Macha once more. Macha is absorbed into a type of Guardian called the Twilight Vagrant. Kite and Elk weaken it, but it transforms into a more powerful Guardian now named the Temptress Lover. Upon defeating the powerful foe, Macha is freed and once again becomes Mia. Mia has lost all memories prior to her first meeting with Kite, but Elk and Kite promise to stand by her despite that.
Characters Introduced in this Volume
- Ω Sickened Imprisoned Fallen Angel
A Data Bug-filled dungeon. Receive Risky Coffee from the Gott Statue.
- Ω Reincarnated Elusive Lyric Poet
Password found on a .hack magazine ad. A Data Bug-filled dungeon. Receive Christmas Card from the Gott Statue.
- In three of the Japanese and American/Europe releases of the game, a character on the cover was obscured by the logo. On the Japanese cover, the logo was at the very bottom and Orca was partially covered, and on the American/European cover, the logo was on the upper part of the cover, completely covering Aura.