Although critically and commercially reviled when released in 1982, genre fans now recognize John Carpenter’s The Thing as a horror classic, thanks in large part to its grotesque visuals and its exploration on the nature of identity. No one in the movie knows who the invading alien has infected and replicated, not even its host, until tendrils sprout from an arm and a toothy maw opens from a chest cavity.Annihilation, the Alex Garland (Ex Machina) directed adaptation of Jeff VanderMeer’s novel, builds on those themes, echoing aspects of the earlier film but refiguring its ideas, moving beyond body horror and toward something more existential.Instead of an arctic base, Annihilation takes place off the Florida coast, where a crashed meteor emits a widening ring of radiation called “The Shimmer”.And where The Thing was an all-male affair (save Adrienne Barbeau voicing a computer chess program), the team here consists entirely of women, each with her own reason for undertaking this certainly fatal mission. For Natalie Portman’s biologist Lena, that reason is to find out what happened to her husband Kane (Oscar Isaac), who, despite being the only soldier to return from a mission into The Shimmer, came back a different person.Kane’s condition sounds troubling, and Lena certainly sees it that way, but Annihilation derives much of its power from its ambivilance about mutation. Change and replication are facts of life, as Lena explains in an early lecture about cellular mitosis, and the image of cells dividing and changing serve as the film’s central visual metaphor — sometimes advancing life and sometimes destroying it, in the form of cancer.This permeable border between life and death, between one identity and another, drives the horror of Annihilation. As in The Thing, infected bodies twist and transmute into terrifyingly uncanny organisms; but in The Shimmer, where animal and mineral and vegetable merge together, the results are often as beautiful as they are unsettling. Radiation infuses Florida swampland with psychadelic rainbows and a yellow haze, mixing flowers of violet and blue into visitor’s flesh. The mutated creatures inhabiting The Shimmer unquestionably differ from things we’ve seen before, but we can’t be fully revulsed by them.Garland further disrupts the audience with the structure of the piece, which seems to follow a fairly straightforward plot: the events of the film are related by a Lena who has already escaped The Shimmer and is being interviewed by another scientist. This storytelling conceit gives viewers certain expectations for its endpoint, establishing from the outset who lives and dies and basic motivations. But then the narrative itself mutates, as heretofore supportive women turn on one another, as new pieces of information are introduce, as Garland uses cameras inside cameras to blur the distinction between teller and tale. The story we thought we were watching, the people we thought we knew, reshape before our eyes.Is that a bad thing? Are these new forms inherently more monstrous than the flawed versions we thought we knew? Annihilation refuses to answer those questions, and instead leaves us struggling with the implications of our answers, leaving us with a creeping sense of dread as our minds change.