A SF short story in epistolary form set in 2045, written as a confession by medical researcher Ikuto Mayuzumi to his mentor, Dr. Tanemei Susuga. Ikuto developed the universal antiviral agent APOLLON and discovered the intelligence-granting transposon ATHENA encoded in the human genome, hoping to save his wife Mutsumi from the disease Richard. However, when APOLLON destroys ATHENA along with all viruses, Mutsumi loses her intellect. Ikuto ultimately arrives at the terrifying truth that human intelligence itself is a product of viral parasitism, and that humanity's construction of an orbital elevator is nothing more than the puppetry of a parasitic organism.

Subject: A letter to my mentor (a memorandum accompanied by private contrition)