Memory loss, extreme paranoia, rapid aging, encroaching psychosis, as well as aphasia and metamorphopsia (distorted speech and vision). With the first inoculation wearing off, these become Brian's experiences as, privately hurtling towards pain and madness, he helps Rebecca look into her father's NZT-related past (having shared the stolen files with her). With Rebecca unexpectedly pulled away into an FBI war game, the side-effects worsen, with the next inoculation withheld till Brian carries out a new assignment: discredit Rebecca.
—statmanjeff