The coming of a Tyranid Hive Fleet is preceded by a smothering psychic signal that envelops entire star systems and disrupts all forms of Warp travel and communication. Swallowed up by psychic-static, whole worlds suddenly go deathly silent, giving no clues as to what is unfolding on the surface below, or of what terrors are about to befall. This is the Shadow in the Warp, and it heralds imminent invasion and horror.