Chemical A0-3959X.91 – 15

Chemical A0-3959X.91 – 15, also known as Prometheus Fire and Agent A0-3959X.91 – 15 and colloquially as black goo or black liquid, is a potent and virulent biological mutagen.¹ It was first introduced in the Alien series film: Prometheus (2012) and appears subsequently in: Alien: Covenant (2017) and Alien: Romulus (2024) in which it is called Z-01.¹

This black, liquid and volatile substance contains a high number of small micro-organisms designed to either create new life-forms or act as a biological weapon.² Just one of these organisms is able to violently and significantly transform and mutate, or simply kill, an exposed life-form.

History

Created and manufactured by the 'Engineers' at an unknown time, but some time before 2093.

2093 (Prometheus)

Discovered on LV-223 by Weyland-Yutani android David.³ Presumably significant quantities still exist on this planet as it housed a number of structures and presumably space ships within them. Only one structure was explored and none were destroyed.

2142 (Alien: Romulus)

Z-01 Was extracted from the remains of the Xenomorph which featured in the original Alien movie.⁴ ⁵ The remains were found and collected by a Weyland-Yutani probe, from the wreckage of the USCSS Nostromo, and brought to the Weyland-Yutani space station Renaissance, which orbits the planet LV-410. This station was destroyed at the end of the film, but some of the Z-01 (in some form) is likely still onboard the Corbelan IV ship that the surviving characters escaped in.

Effects of Exposure

Exposure typically leads to one (sometimes two) of three highly unpleasant outcomes, detailed next.

Rapid Mutation

A host life-form is transformed and mutated, often in less than a day, into an aggressive and highly violent creature that seeks out and attacks other life-forms. These mutated creatures are commonly known as an anathema, abomination or monster. They are typically extremely strong, fast, agile and resilient and very hard to kill. Any injuries or diseases suffered by the original life-form are usually healed or cured during the mutation. Victims may also gestate a parasitic organism, covered next.

Parasite Gestation

Whether mutated or not, a host may gestate a fast-growing, parasitic life-form. In most cases the parasite's 'birth' is violent and leads to the host's death. As with mutation, any injuries or diseases suffered by the life-form are usually healed or cured during gestation, not that this provides any lasting benefit to the soon to die host. &7LeW*rMmrpvfS$

Death

Based on unknown fitness criteria, if a host is not suitable for mutation or gestation, it is simply killed.