- "I have a feeling that the key to it is somewhere in... The World."
- — Kite —
.hack//INFECTION (.hack//感染拡大Vol.1) (Japanese title: Infection Expansion) is the first of the four-part video game series that launched the .hack franchise.
The game should come packed with the first Liminality disc, 'In the Case of Mai Minase'. In Japan, players would receive a figure set that recreated the cover of the game and also seven illustration cards if they reserved it.
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.
After Kite finds out that Yasuhiko fell into a coma, he returns to The World to find answers. After posting his situation on the BBS, he meets BlackRose, who urges him to take her to the field Δ Hidden Forbidden Holy Ground. There, the two are attacked by a monster that entered the area via an irregular portal. A player named Balmung appears and defeats it, but it's viral core restores it's energy and transforms it into a Data Bug, giving it unlimited Hit Points. Balmung, though as strong as he is, cannot defeat it in this form. At this point, Kite's Book of Twilight activates and gives him the ability to Data Drain. With this new ability, the Data Bug becomes a normal monster, and Balmung is able to defeat it again. Balmung accuses Kite of being the hacker responsible for the degradation of The World. BlackRose responds by calling him ungrateful to the one who saved his life, and Balmung leaves without taking any further action. Upon leaving the chapel, the mysterious hacker Helba tells Balmung that Kite is the friend of Orca. Inside the chapel, Kite tells BlackRose about what happened to Orca, and she offers her assistance to Kite.
Kite checks up on the BBS and finds his post deleted. Following clues found elsewhere on the BBS, the two head to Δ Expansive Haunted Sea of Sand and encounter a Headhunter Data Bug. A Wavemaster named Mistral witnesses them defeating it and gives Kite her Member Address.
As Kite continues searching for clues, he helps out a haughty Heavy Axeman named Piros and is given his Member Address. After returning from the mission, he receives a threatening e-mail telling him to stop asking questions. He also receives an e-mail from CC Corp informing him that he has won a rare item from the "Level Up Campaign." The item, Book of Law, supposedly raises his level, but Kite receives an installation error preventing him from using it.
Kite once again returns to Mac Anu and meets up with a pair of PCs named Elk and Mia. Mia displays her ability to see Kite's bracelet and later e-mails him, telling him to go to Δ Boundless Corrupted Fort Walls alone. Kite does so, traversing the dungeon solo and Data Draining the Red Wyrm Data Bug he finds at the bottom. It seems that the dungeon was a test to see Kite's power. After returning to Mac Anu, Mia teaches Kite how to use Virus Cores to Gate Hack into Protected Areas. After Mia and Elk give Kite their Member Addresses, Kite Gate Hacks into Δ Closed Oblivious Twin Hills, a corrupted area posted on the BBS. At the bottom level of the dungeon is yet another Data Bug.
At Mac Anu, Balmung approaches Kite and asks of his relationship with Orca and about his ability to Data Drain. Kite tells him everything, and Balmung walks away, reminding him that the power the bracelet possesses is the same one that put Orca into a coma. As Balmung leaves, Helba appears before Kite, warning him that he is always being watched and that he should be especially wary of Lios.
Following another clue found on the BBS, Kite and BlackRose go to the newly reopened Θ Server and to Θ Quiet Eternal White Devil. They are disappointed as at the bottom of the dungeon is nothing but a dead end.
Kite meets with Elk at Mac Anu, where Elk asks him to get rid of a Data Bug found in his favorite field, Δ Plenteous Smiling Hypha. Upon gating in, Elk reveals that it was a lie and asks Kite to give him the bracelet so Mia would spend more time with him. Sudden static indicates a problem within the area and the two decide to enter the dungeon. At the bottom they find Mia fighting with a Killer Snaker Data Bug. Upon defeating it, Elk rejoins Mia after realizing that she is still his friend.
As Kite returns to Dun Loireag, he is given the Book of Iron by Apeiron after Mistral unsuccessfully attempts to buy it from him. When Mistral returns and sees she lost her chance, she tells Kite to bring her to Θ Collapsed Momentary Spiral, where she gets to see first-hand his ability to Data Drain a Data Bug. Mistral thinks the ability was given to him during an event and leaves to salvage her burnt dinner in real life before Kite has the chance to explain.
Kite gets another e-mail from BlackRose, who contacted the poster of the dead end keywords. The post was edited by an administrator and the original keywords in the post were Θ Cursed Despaired Paradise. At the bottom of the area's dungeon is a white room with a bed and teddy bears in it. Within the room are two notes: one left by Harald Hoerwick and another that is an excerpt of the Epitaph of Twilight.
Kite follows a BBS message from Bob, who wants to meet Orca. Kite tells him about the situation and finds out that Orca was investigating something hidden in The World. He is told that Linda has more information. Linda tells Kite of a room Orca was investigating, but upon entering the room, Kite finds that the area's data was tampered with, leaving holes and patches in the room's coding. Kite finds an illegible fragment of the Epitaph there and leaves.
On the BBS, a player named Meg is looking for a player named Alph, who couldn't be contacted. BlackRose contacts her and brings Kite to meet with her to find out what area Alph was at before she went into a coma. Before the two meet with her, she was seen conversing with what looked like a Mac Anu shopkeeper. Meg tells them that she couldn't tell them the keywords right now and that she posted them on the BBS. The post was unfortunately deleted. Helba, however, retrieved the data and told Kite that the keywords were Θ Chosen Hopeless Nothingness. At the bottom of the dungeon, Kite and BlackRose found Aura, who was attacked by Skeith. This time, she did not escape and was split into three segments by Skeith's Data Drain. There would be no interference from Helba, so Kite's party had no choice but to fight.
After a long fight, Kite was able to Data Drain Skeith and defeat him. Skeith's stone body melted into the ground as another, more fearsome enemy appeared: Cubia.
Characters Introduced in this Volume
- Δ Voluptuous Her Remnant (Rusty Nails in a chest and Kagayuzen from the Gott Treasure)
(Keyword is found on the back of .hack//SIGN DVD 1, Login.)
- Δ Hideous Organ Market Scaffold (Ice Bar)
- Θ Dog Dancing Passionate Tri Pansy (Soul Blades and Ceramic Helm)
- There are several inconsistencies between the Japanese and US trailers. The returning shards of Data Drain were blue/green. Skeith was still using his Japanese Celtic cross.Players could visit the 4th Root Town, which debuts in Outbreak. Yuki Aihara and Kyoko Tohno were leaked in the E3 character promo image for Infection.