God-fearing tornado clouds brew overhead as rain yellowed with motor oil begins to fall onto Curtis' (Michael Shannon) opened palms. A portentous warning of something wicked this way coming, or early signs of the same emotional disorder his mother (Kathy Baker) was stricken with when she was around his age? "Take Shelter" wrestles with this question throughout, writer-director Jeff Nichols teasing both possibilities while keeping viewers on edge. Nichols' storytelling relies on a mounting atmosphere of slow-burn intensity and an attention to people rather than plot points, his sensibilities lying next to, for example, Steven Spielberg's in 1977's "Close Encounters of the Third Kind." At certain points, the film threatens to turn into a standard-issue melodrama about mental illness, but the subject is tackled from a livelier, more creative place and defies the easy, obvious route. The point isn't whether or not Curtis is mad, anyway, but how he must come to terms with what is happening to him, and perhaps the world. Sane or not, there will be few easy exits from his ultimate fate.

A blue-collar construction worker living in rural Ohio, Curtis has made an honest life for himself and seamstress wife Samantha (Jessica Chastain), the two of them currently coming to terms with young daughter Hannah's (Tova Stewart) recent hearing loss. In the process of learning sign language, they cling to the hope that corrective implants may help her if they can get approved for it. When Curtis starts experiencing restless sleep and vivid nightmares that bleed into his waking hours, he becomes alarmed. He recognizes the dreams themselves aren't real in the literal sense, but they don't seem like figments of his subconscious, either. Feeling constantly paranoid as if someone is watching him, hearing and seeing things that aren't really there, Curtis secretly seeks medical help for his worries, then begins to fixate on building a massive storm shelter in his backyard for what he fears could very well be the oncoming apocalypse. His erratic actions worry Sam and alienate friends, family and co-workers, putting into jeopardy the insurance they so desperately need to pay for Hannah's surgery.

"Take Shelter" is a psychological horror picture either about a sick mind, the end of days, or both. Whatever the case, the film blankets itself with a pall of hopelessness, kind of like a person's inescapable tragic destiny barrelling straight for him or her. There is an off-balance gravity and an underlying supernatural suggestiveness to director Jeff Nichols' methods. When Curtis dreams of the family dog attacking him and suffers from a sore arm the following day, he can't help but wonder what's going on. Flocks of birds gathering in the restless sky and falling to their deaths on his lawn, unrecognizable mystery men out to get him and his daughter, storms and cyclones teasing the destruction of the town—Curtis is beset by further hallucinatory experiences that leave him just as perplexed, if maybe a little more keenly aware of the potential danger looming, as his loved ones are. One of the interesting angles of Nichols' script is his treatment of Curtis not as an indifferent vessel to lob craziness onto, but a genuinely scared man who wants to know what is happening to him before he potentially loses himself in the process. Proactive rather than indifferent, he sees a physician for medication to help him sleep, he does research in the library about mental disorders, and he visits his mother in assisted living to question her about the events that led to her having to go away for treatment of schizophrenia when he was just a kid. He doesn't want to worry Sam, but how can he not as his thoughts grow disorganized and his obsession over something awful drawing near refuses to cease?

Michael Shannon (2010's "The Runaways") is exceptionally committed to the role of Curtis, the same way he disappeared into his Oscar-nominated turn in 2008's "Revolutionary Road." Shannon isn't the warmest or cuddliest of performers—he is an intense character actor who happens to be the lead here—but that makes his drive to protect his wife and daughter all the more touching somehow. To see him actively attempting to stand by them, as in a scene where he and Sam visit a support group for parents of deaf children, is to fully grasp and understand what he has to lose if he is, indeed, going crazy. As Samantha, Jessica Chastain continues her practically unheard-of breakthrough year. With "The Tree of Life," "The Help," "The Debt," and now "Take Shelter," Chastain has given four great performances playing four distinctively different characters, each one so authentic that it is as if she's not even the same person from one film to the next. Portraying a young woman who wants to rally around her husband and hold onto the good in their relationship, Chastain nevertheless internally embodies Sam's whispered desperation. She doesn't want to belittle Curtis, or talk down to him, but it is imperative that she at least attempt to get through to him before it's too late. In a predominately insular motion picture that wavers little from Curtis and Sam, support is steadfast but sure to be overlooked. As Curtis' brother Kyle, Ray McKinnon (2011's "Footloose") shares a touching single scene with his brother that astutely encapsulates their bond since childhood, and Kathy Baker (2008's "Last Chance Harvey") movingly plays mother Sarah without any of the clichéd tics, body language and histrionics normally found in cinema's roster of mentally ill characters.

As must occur, a nasty storm eventually does rustle up and underground shelter is sought. Is the ruckus above simply passing by or staying put for good? Implosive and disturbing in its hushed treatment, Curtis and Sam face off the following morning, a careful, riveting balancing act between a wife who wants to do nothing but come off as supportive of her significant other even as she must convince him to open up the cellar doors if she and Hannah hope to escape. If she succeeds, what awaits them on the other side? Where "Take Shelter" goes from here is lip-bitingly unpredictable just when the viewer suspects he or she knows where things are headed. By the end, all that has transpired is less about madness than understanding, the trust between loved ones the critical ingredient in staying together, and wanting to. Whether their days are about to end in moments or fifty years from now, at least they've got that.