You know that feeling when you're home alone and you hear a bump in the night that you tell yourself is really nothing? Still, it stirs a chill all the same, a sensation of doubt that draws your eyes to that dark corner as your mind lingers on what might lurk there. James Wan knows your fear, and with "The Conjuring 2," he toys with it, spinning a tension so suffocating you'll gasp for relief. And he'll grant it, but at a cost.

Based on real-life accounts, "The Conjuring 2" reunites horror fans with Ed and Lorraine Warren, paranormal investigators who rescue families from the demonic spirits that haunt them. Lately, Lorraine (Vera Farmiga) is afflicted with troubling visions of a razor-toothed nun and the violent death of her beloved husband Ed (Patrick Wilson). To save him, she's tempted to leave exorcisms and séances behind -- that is, until they hear the desperate pleas of a family of five in an impoverished corner of North London.

At night the children of single mom Peggy Hodgson (Frances O'Connor) are plagued by strange assaults that wake them from their sleep, rip them from their beds and leave bloody bite marks. Despite Lorraine's reluctance, the world-famous Warrens travel across the pond to determine whether this is a true paranormal attack or -- as skeptics accuse -- a horrific hoax meant to bring the family fame and fortune.

The creepy adventure kicks off with the Warrens in the thick of the Amityville haunting, giving Wan the opportunity to unnerve audiences from the start with his malevolent nun. After some sharp scares, the focus shifts to a story of two families, the Warrens and the Hodgsons: one a wealthy American clan that boasts a luxurious home and a two-parent household, the other English, and scraping by in a rundown house with peeling paint and a pernicious poltergeist. Taking a cue from the horror greats of the '70s like "Jaws" and "The Exorcist," Wan embeds us with each family, so the danger it faces will feel all the more devastating.

Farmiga and Wilson are once again wonderful together as Lorraine and Ed, serving as brilliant foils for each other: She's empathetic but thoughtful, and brave but brash, which sometimes leads to foolhardy action; one would be without the other. So even as they watch a little girl quake with fear over the "crooked man" who overtakes her body and isolates her from family and friends, you can understand Lorraine's hesitation to get too close to the Hodgsons.

Too often underrated, O'Connor savagely sinks her teeth into the role of Peggy. In turn fearsome and afraid, she ferociously defends her kids against an unseen assailant, then crumbles at the cruelty that is her helplessness. When Ed matter-of-factly tells her the misery of her husband's abandonment may have attracted this shady spirit, she spits with rage about being kicked when she's down. Yet a fire in her eye signals she hasn't been defeated. Meanwhile, the Hodgson children are largely a blur of screams and regrettable '70s clothing, save for poor Janet (Madison Wolfe), the crooked man's favorite victim. With a steely gaze stippled with tears, Wolfe reflects O'Connor's blend of battered and defiant, cementing the human stakes of this haunted house tale.

On a horror level, this sequel is sensational. Wan knows exactly how to employ smooth camera moves to stir anticipation, and how to utilize whip-pans for shocking reveals. Better yet, he's a step ahead of his audience: He knows how we expect gags involving the reflections of ghosts and the manipulation of children's toys to play out. But rather than delivering on those expected beats, Wan offers new twists to make these old tropes freshly frightening. Patience and silence are teased out to make the mundane terrifying, and thus a knock on the door, a squeak of a stair, the shrill ring of an old-school telephone, or a screech of a rocking chair can be sounded with a uniquely chilling effect. Darkness is employed like a threat, letting our minds run wild with what might be looking back at us from its depths.

Wan is a master of suspense and terror. And with "The Conjuring 2," he's not only redefining how we think about sequels -- offering a story that's richer and a ghost that's more terrifying than those in the original -- but also striving to make his masterpiece. This is his "Exorcist." Wan wants this to be as emotionally riveting as it is frightening, a horror movie so good that it'll force snobs to reevaluate the genre's merits. You can feel his efforts, his earnestness, his exuberance.

However, "The Conjuring 2" is just shy of being flawless. At 2 hours and 13 minutes, the film is a bit bloated and overlong, studded with repeated emotional beats of doubt and bonding, as well as monologues for even minor characters. I suspect some of that can be attributed to Wan's dedication to do right by the real-life Warrens and their legacy. But it regrettably snarls his otherwise tautly suspenseful pacing in a lagging second act.

Still, "The Conjuring 2" is electrifying and frightening. Wan's horror is enhanced by his humanity, breaking up spooky set pieces with lighthearted moments, such as out-of-their-depths police officers fleeing the Hodgson home with a determined but humbling efficiency. That focus on the people as well as the poltergeist gives a real wallop that makes "The Conjuring 2" the scariest movie I've seen all year.

"The Conjuring 2" opens June 10.