- "It's too late. I don't need you anymore."
- — Morganna Mode Gone —
Tempest is the twentieth episode of .hack//SIGN.
As Tsukasa and Subaru spend more time together, Mimiru, who is playing with Bear, laments over the Key of the Twilight and how distant everyone else has become. She is still determined to help Tsukasa find a way to log out, and turns down Bear's offer to see the real Tsukasa, remembering her promise to shop at Shimokitazawa when Tsukasa is able to. Meanwhile, Sora gets BT to aid him in recruiting the wandering Silver Knight as a pawn, forming an unlikely alliance between the three. BT ultimately gets Silver Knight to comply by telling him that gaining the Key of the Twilight may restore the Crimson Knights to glory.
At Hulle Granz Cathedral, Subaru informs Bear about the time she has spent with Tsukasa. Bear approves of her actions, believing that their relationship will help Tsukasa leave The World. Perhaps motivated by Subaru and Mimiru, Bear decides to call Mimiru, BT and Crim together to discuss the renewal of the search for the Key of the Twilight.
Everyone called by Bear agrees to once again search for information about the Key of the Twilight. Unbeknownst to them, BT is also working with Sora, who plans to use Silver Knight and the remaining forces loyal to him to beat Bear's group in finding the Key.
After their meeting, Mimiru encounters Subaru, who regrets escaping the field when Morganna arrived. Meanwhile, Morganna punishes Tsukasa for bringing Subaru. She coldly tells Tsukasa that she no longer has any use for him and Data Drains him over Aura's bed, leaving him a mentally broken shell.