Alien Syndrome

An unassuming planet, Earth, naively occupying its corner of the galaxy, engaged in its worldly activities and anchored within its span of knowledge, as indeed it stands today, conversant with the fantasies of science-fiction writers: of interactions between planetary civilizations, of invasions of Earth or intervention from super-beings and a glimpse of superior knowledge; all incongruous with its daily experience. Now, to be the victim of a chance decision and to be abruptly shaken from its mundane existence and relative security by a confusing and mysterious interference, culminating in a fearful threat which could seemingly only relegate its fate to the pages of the Book of Doomsday.
Can computer wizard Alvin come up with some answers in time before Earth is destroyed?