Ryan Reynolds is renowned these days as a confirmed A-list cutup, but he’s always possessed a more serious acting side. “Possess,” in fact, might be an apt watchword for his triple-identity leading role in the 2015 sci-fi thriller Self/Less, a body-swapping thriller of a science fiction film that weighs the value of extending life beyond its natural limit… even if it means cutting short another life to do it.

Directed by Tarsem Singh (The Cell, Mirror Mirror, NBC’s Emerald City) as a taut action thriller that smartly scales back Singh’s usual gift for visual extravagance, Self/Less (streaming here on Peacock) is miles better than its humble Rotten Tomatoes score, and easily punches far above its lightweight $26 million production budget.

Critics have taken issue with the idea that bloody shoot-outs and explosive car chases could somehow resolve the heady science fiction questions that the movie poses right from the start, but they’re wrong: All that action is leading somewhere, and Reynolds’ character uses it to make an ethical choice that delivers satisfying answers by the time the credits roll.

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Ryan Reynolds’ big body swap: Whose life is it anyway?

Reynolds and Ben Kingsley both star as New York money mogul Damian Hale, a wealthy older man (played early in the film by Kingsley) with tons of unresolved personal baggage that’s all about to be left dangling after he gets a terminal cancer diagnosis. As luck (and gobs of money) would have it, though, he gets a chance at virtual immortality, thanks to a mysterious medical guru named Albright (Matthew Goode), who offers Damian a slot in a super-secretive experimental swapping program that’ll transfer Damian’s consciousness into a younger, more capable body.

Whose younger, more capable body is it? Damian doesn’t ask, seemingly content to presume that his new skin digs come with a cruelty-free, science lab-grown pedigree. After going through with the procedure (and staging his own public death to assure his new identity its own fresh start), he awakens in Reynolds’ body: Young, fit, and only mildly beset with weird hallucinations that Albright’s post-recovery regimen of proprietary red pills are supposed to cure.

For Damian — now adjusting to his second life as an anonymous New Orleans resident under the first-name alias “Edward” — those hallucinations start to feel a lot like actual human memories. In fragmented flashbacks far removed from any New York high society experience that Damian’s ever known, he “sees” the past through the eyes of a young soldier, as shattered scenes of desert combat, a wife and daughter back at home, and unsettling interactions with Albright all invade his consciousness. Taken together, it all suggests that the body he’s inhabiting once belonged to someone else — and someone whose skin and bones definitely weren’t grown in a lab.

Damian (aka “Edward”) follows his intuition and begins a little unprescribed sleuthing, the very thing that Albright — who just wants him to lie low and and obediently take his hallucination-halting pills for a while — recommends against. Following visual cues from his flashbacks, he tracks down the woman and child from his borrowed memories to a farm outside St. Louis, where their awkwardly emotional family “reunion” is immediately cut short by Albright’s hit squad, sent to snuff out the doctor’s rogue test subject (as well as his family) before Damian starts finding real answers.

The trio escapes and goes on the run, with Damian learning, between paranoid pit stops, that he’s living inside the body of a soldier named Mark. In well-directed scenes far less confusing than they have any right to be, Mark and his understandably disoriented wife Madeline (Natalie Martinez) piece together all the secrets the movie’s been keeping: Unbeknownst to Madeline, Mark agreed to a devil’s bargain with Albright; one that staged his own death and handed over his body as one of Albright’s next science projects — all in exchange for costly but lifesaving medical treatment for Anna (Jaynee-Lynne Kinchen), the couple’s young daughter.

The rest of the movie is indeed a wild and extended action ride, but it’s one compelled by good old-fashioned whodunnit questions. Like Michael Douglas in David Fincher’s The Game (1997), Damian/Edward/Mark knows he’s trapped inside a bigger puzzle than any of his identities (or Mark’s actual family) ever signed up for, and — just as importantly — he’s far past caring about clinging to the affluence-enabled naïvety of Damian’s former life. All bets are off for preserving his own safety, so long as he finds a way to save Mark’s family… and, of course, to orchestrate one final showdown with the science-crazed madman behind the curtain.

Anytime you’ve got multiple personas striving for sci-fi squatter’s rights to just one body, all but one of them inevitably has to die. No spoilers here, but Self/Less definitely doesn’t leave viewers hanging on that front. It’s safe to say, though, that Damian finds a way before the credits roll to handle his New York baggage, give Mark’s family a future, and definitively fire (you’ll see what we mean) his wacky, immortality-obsessed doctor. Through it all, Reynolds juggles his alternate egos with a subdued, mission-focused drive that switches between characters not like some Jim Carrey-channeling, over-the-top comedian (though we definitely know he's capable.) Instead, he plays it cool like a guy (or guys) in search of answers… and by the end of Self/Less, he — and we — get them.

Stream Self/Less here — and for even more Ryan Reynolds body-swapping fun, check out fantasy rom-com The Change-Up, also streaming here on Peacock.