BLIT (short story)

BLIT (which stands for Berryman Logical Image Technique) is a short science-fiction story written by author David Langford. It features a setting where highly dangerous types of images called "basilisks" have been discovered; these images contain patterns within them that exploit flaws in the structure of the human mind to produce a lethal reaction, effectively "crashing" the mind the way a computer program crashes when given data that it fails to process.

Langford's later short story comp.basilisk FAQ, first published in Nature in December 1999, mentions William Gibson's Neuromancer (1984), Fred Hoyle's The Black Cloud (1957), J. B. Priestley's The Shapes of Sleep (1962), and Piers Anthony's Macroscope (1969) as containing a similar idea. Examples not mentioned include the short story White Cane 7.25 (1985) by Czech writer Ondřej Neff, A. E. van Vogt's War Against the Rull (1959), and John Barnes' Kaleidoscope Century (1996). The idea of a "lethal image" is also proposed as a weapon against the Borg in the Star Trek: The Next Generation episode "I, Borg". It is also similar to the plot of the 2002 horror film The Ring.

Authors Ken MacLeod and Greg Egan both acknowledge the idea with a specific reference to Langford – "the Langford hack" in The Cassini Division (1998) and "the Langford Mind-Erasing Fractal Basilisk" in Permutation City (1994). Charles Stross also refers to a type of magical ward known as the "Langford Death Parrot" in The Fuller Memorandum (2010) and "Basilisk attacks" with "Langford fractals" in Accelerando (2005).

The story has three sequels, What Happened at Cambridge IV, comp.basilisk FAQ, and Different Kinds of Darkness. The last story imagines a post-apocalyptic world where BLIT images are everywhere, and millions have already been murdered by terrorist attacks utilizing them. Television and the internet have been outlawed due to the proliferation of BLIT images. In order to protect children, special chips have been planted in their brains that creates a subjective and artificial darkness (which the children call "type-two darkness") to obscure any possible BLIT image they may inadvertently look at. The main characters, all school children, form the "Shudder Club", where they take turns looking at a BLIT image to see how long they last, inadvertently vaccinating themselves against them.