Rachel Weisz stars in "Dead Ringers" on Amazon's Prime Video.
CNN  — 

Twice the Rachel Weisz is a pretty good sales pitch, but it’s about all that “Dead Ringers” – a gory gender-flip reimagining of David Cronenberg’s even gorier 1988 movie – has going for it. Turned into a limited series for Amazon’s Prime Video, the show never overcomes the “Why” factor, other than the allure of seeing its star inhabit a dual role as eccentric twins.

Although the gender has changed, the names haven’t, with Weisz playing Elliot and Beverly Mantle, a pair of gynecologists who, here, are at the forefront of researching best practices for reproductive health as part of a shared crusade to “change the way that women birth.”

While the two are identical – and the camera techniques for letting Weisz portray both exhibits a state-of-the-art level of smoothness – their personalities differ greatly, with Elliot the more hard-charging and confrontational of the two, at one point explaining, “My sister says I’m a hungry person. I like to feast. But just once.”

That attitude spills over from work, and a willingness to explore questionable practices in terms of medical ethics, to their personal lives, with the little matter of nobody, even potential lovers, being able to tell them apart.

While the latter wrinkle stood at the heart of Cronenberg’s twisted tale (itself adapted from a 1977 novel), it’s more muddled by this all-over-the-map version of the story, which hinges in part on the strain between the beyond-close siblings thanks to Beverly’s new-found relationship with Genevieve (Britne Oldford), an actress who is understandably suspicious of Elliot.

Adapted by writer/playwright Alice Birch, and counting Weisz among its executive producers, “Dead Ringers” lets Weisz sink her teeth into the kind of showy role that has historically been catnip for actors. Yet it comes in the service of a project that labors to stretch the idea over six episodes, and too often feels as if it’s being provocative and edgy for the sake of it, leaving the doctors soaked in blood.

Indeed, while the issues surrounding childbirth and bodily autonomy are obviously timely given the debate over abortion rights, the series falls into a strange nether realm between reality and science fiction that initially worked in something like “The Handmaid’s Tale” but, as executed here, blunts its sense of relevance.

At its core, “Dead Ringers” still deals with questions of identity through the prism of the symbiotic nature of Elliot-Beverly relationship. The dexterity of Weisz’s take-no-prisoners performance makes it hard to look away, but beyond that the show doesn’t make much of a case for feasting on it once, much less twice.

“Dead Ringers” premieres April 21 on Amazon’s Prime Video.