(hb; 1998, 2005: third book in the Ring Cycle; translated by Glynne Walley)
From the inside flap:
"In Loop, the killer [virus, from Spiral,] mimics both AIDS and cancer, in a deadly new guise. Only one person, Kaoru Futami asks where the disease could have originated. The youth, mature beyond his years, must hope to find answers in the deserts of New Mexico and the Loop project, a virtual matrix created by scientists. The fate of more than just his loved ones depends on Kaoru's success..."
More science fiction than horror, Loop completely reframes the ideas, tones and storylines of the horror-based Ring and more-scientific-than-scary Spiral. Initially, the tightly-plotted Loop didn't grab me as quickly as the first two books in the Ring series, but boy, when it did -- about a quarter of the way in -- it was damn near impossible to set down.
This is a clever, mindblowing finish to a high-mark-in-science-fiction/horror trilogy, which makes stunning use of subliminal imagery and themes (spirituality, science, society, and our relationships to these intermingled notions).
Own, don't borrow, these books. While Ring, Spiral and Loop can also be read as stand-alone novels, they're better read in order, starting with Ring.
Followed by the story anthology Birthday.