If you’ve been waiting for the latest piece of genre obsession by way of prestige TV, get ready for The Terror. The tradition of the handsome, impeccably cast period drama gets a horror makeover in the new AMC event series, which adapts from Dan Simmons celebrated novel of the same name to create an immersive world of antarctic nautical nightmare.

Produced by Ridley Scott and inspired by the true-life tale of the H.M.S. Erebus and H.M.S. Terror, which famously disappeared in the ice on a mission to discover the fabled Northwest Passage almost two centuries ago (the ships were only just discovered in 2014), The Terror sketches out the fantasy horror version of a nautical journey gone wrong gorgeous, excruciating detail. From the ravages of nature constantly biting at the men’s heels to the bitter dynamics between the crew that sow the seeds of their own downfall, showrunners Dave Kajganich and Soo Hugh take their time with the details of the torment that unfolds.

At the helm of the expedition is Captain John Franklin (Ciarán Hinds), who commands the Erebus with good cheer, but poor sense. He’s genial and his crewmen like him, but he’s also an obvious social-climber who’s ill-prepared to lead an expedition this important and, worse yet, this dangerous. At his side, his opposite, is Francis Crozier (Mad Men standout Jared Harris in a long-deserved lead role), who captains the Terror. He’s a proud, experienced sailor with leagues of experience on Franklin, but he’s a depressed, often off-putting man, and a drunk, with none of his superior’s charms. He’s also Irish — a fact that has kept him from rising to the top in personal and professional circles throughout his life, fueling a deep-seeded resentment. On top of their professional difference, the pair shares a heated personal background, and their inability or unwillingness to see eye-to-eye sets the stage for their journey’s undoing. When Crozier warns Franklin that they are headed to almost certain doom, the undistinguished first in command pursues his ambitions over his common sense with a reckless determination to go forward and thus, with a grin and confidence, he seals their fate.

If Harris and Hinds make for a compelling lead duo, The Terror is impeccably cast from top to tail, and the rest of the roster is filled out by an equally talented lot. The series takes the time and care to establish credible inner life to the crewmen of the two ships, and their overlapping conflicts and collusions are the ever-churning source of intrigue and menace that proves the greatest source of horrors once the shit hits the fan. Outlander favorite Tobias Menzies is James Fitzjames, third in the chain of command, whose vanity and indulgent self-praise overshadows his underlying decency. Other standouts include Cornelius Hickey (Adam Nagaitis), a charming but irascible young crewman who harbors portent secrets and share’s Crozier’s resentment — and his desire to climb the ladder, and the kindly Dr. Harry Goodsir (Paul Ready), who administers care diligently, offering a welcome bit of tender-heartedness among all the stiff upper lips.

In a deeply unsettling, downright haunting early sequence, we see the tenderhearted doctor caring for an ill crewman, whispering words of comfort in the young man’s ear as he lies on his deathbed. But the young man cannot be comforted, and wracked with visions we can neither see nor understand, he dies screaming in exquisite torment with Dr. Goodsir looking on helpless horror. This sequence, along with the expertly paced hallucinations of diver in a gorgeous old-timey rig, set the tone for The Terror — one of bleak, piercing panic and the threat of something incomprehensibly dreadful just beyond the veil of reality. Our dear Dr. Goodsir also takes an interest in a mysterious Inuit woman who comes aboard under terrible circumstances, and it’s through her that The Terror increases the scope and force of its horrors, peering through that veil to otherworldly frights.

Given the name Lady Silence (Nive Nielsen), the native woman is brought aboard the ship after a violent attack by a horrifying monster known as Tuunbaq, and it’s here that The Terror opens up its tightly crafted world of horrors to spiritual and existential nightmares. Without delving into spoilers, these explorers have tread into a realm and reality for which they are utterly unprepared, and as The Terror unfurls the layers of Tuunbaq’s mythology, the mounting sense of horror deepens into a well-earned dread. Likewise, the creature’s design first appears simplistic, perhaps disappointing, but the more intimately we see the creature, the more disturbing and impressively realized he becomes.

Indeed, everything in The Terror looks spectacular. The production value is gorgeous and the series’ below-the-line team crafted a completely immersive world, from every richly detailed nook and cranny in the ship to the sprawling, icy landscapes of the Arctic. The series also boasts stunning cinematography throughout, creating contrasting settings of flickering, lamplit darkness and blinding white vistas of endless snow, neither of which offer any comfort from the cruelties of man and nature. However, The Terror doesn’t play its hand too obviously and keeps the visual language rooted in the tradition of drama over horror. There are no glaring indicators of the hell that lies in wait at any given moment. To the contrary, the series is shot as if it were any other prestige period drama, which makes it all that more surprising and unnerving when the horror creeps in.

As for the horror, it comes early, but slowly. The Terror may be pitched as a nautical adventure, but these ships become ice-locked quickly and from there, everything more or less stays put. It festers in a single spot with deliberately paced action while the strings of intersecting character drama, mythological, and natural horrors pull tighter and tighter until you’re left with no room to breathe. It’s not long before the unforgiving cold is the least of their worries — though the easily torn chunks of flesh and tales of exploding teeth never do lose their impact. However, for some viewers, this will no doubt play out at a too slow, too determined pace. The Terror takes its time, it knows the dark dreariness it’s headed toward and it’s in no hurry to get there. You will know quickly if the series isn’t paced to your liking, but if you can stick with it, The Terror is easily one of the most downright scary shows to hit TV in years.

There’s no shortage of TV series exploring the far reaches of the horror genre these days — in fact, genre TV has become the home to many of the most popular series on the air — the demon-hunting adventures of Stranger Things, the wild concepts and indulgences of American Horror Story, and of course, the survivalist melodrama of long-standing ratings juggernaut The Walking Dead. But even if these series are culled from the tradition of horror, they are rarely scary. The Terror does not have that problem. This show attacks fear slowly, from all angles — there’s the slow-building tension between the ships’ crew, the unrelenting violence from nature, and the supernatural element that elevates it all to a heightened realm of psychological and spiritual violence. This is a series that fills you with unrelenting dread. As the title suggests, The Terror is interested in fear itself, how it transforms us, how it turns us cruel and savage. The Terror investigates that fear on many fronts, and in doing so it conjures a piercing dread, both familiar and inconceivable; a portrait of man and nature at their cruelest and coldest.

Rating: ★★★★★ Excellent