The Sus-an Membrane, also called the Hibernator or the Suspended Animation Membrane, is the 12th of the 19 genetically-engineered organs created from a Space Marine Chapter's gene-seed that is implanted into a normal human adolescent male to transform him into a Neophyte of an Adeptus Astartes Chapter. Initially implanted within the Neophyte's cranium, this organ eventually produces a membrane comprised of genetically-engineered neural tissue that merges with the recipient's cerebrum, becoming a full part of his neural architecture. The organ's functions are ineffective without follow-up chemical therapy and training by a Chapter's Apothecaries, but with sufficient practice and instruction a Space Marine can use this implant to enter a state of suspended animation, consciously or as an automatic reaction to extreme trauma, keeping the Space Marine alive for many standard years, even if he has suffered otherwise mortal wounds. Only the appropriate chemical therapy or hypnotic auto-suggestion can revive a Space Marine from this state. The longest recorded period spent in suspended animation was undertaken by Battle-Brother Silas Err of the Dark Angels Chapter, who was revived after 567 standard years in Sus-an hibernation.
- Codex: Space Marines (5th Edition)
- Warhammer 40,000: Compendium (1st Edition)
- White Dwarf 98 (UK), "The Origins of the Legiones Astartes" by Rick Priestley