Justin Theroux in a scene from “The Leftovers.” (Paul Schiraldi/HBO via Associated Press)

If our world was suddenly shown to be a fake, how would we cope? That’s the question posed by two ambitious television shows. “The Man in the High Castle” and “The Leftovers” are both adaptations of somber novels about alternate realities, but differ considerably in how well they translate to the screen.

“The Man in the High Castle” posits that the Nazis and their Japanese allies won World War II, bludgeoning the United States into surrender by dropping an atomic bomb on Washington, D.C. Prostrate, the USA is carved up into the Greater Nazi Reich in the east, the Japanese Pacific States in the west and a neglected neutral zone in the middle.

Philip K. Dick set his novel, the source text for the television show, in the culturally blended Pacific states of an alternate reality 1962. Infused with ideals of moral probity and social place, this new West Coast offers a stark contrast to the manic Nazi empire, with its gleaming rocket ships, blood-soaked global schemes and lethal internal power struggles. The Japanese know war to be in the Nazi nature. Having dropped the atomic bomb once, it’s only a matter of time before they turn on their erstwhile allies and do so again.

Hawthorne Abendsen, the man in the high castle himself, is unconvinced by the new world. He writes a book of counter-history in which the Nazis lost the war. More an act of befuddlement than subversion, Abendsen sketches his story by consulting the Chinese oracle the I Ching on every plot point.

Dick’s characters have the queasy feeling that there is something inauthentic about their world. A high-ranking Japanese official glimpses an alternate-universe San Francisco that may or may not be our own: an ugly freeway where before there was a park, a new harshness in the walk of the city’s inhabitants, a casual piece of abuse from a white American. He experiences it as a temporary disorientation, a “disturbance of the inner ear.”

Sadly, as Laura Miller points out, much is lost in the translation to television. Playing as a standard occupation/resistance drama, which could easily be set in the actually occupied states of World War II, the show is visually striking but ultimately disposable.

“The Leftovers” is the superior series, building in its second season (the finale is Sunday night) on a brilliant beginning. Two percent of the world’s population has disappeared in a Rapture-like event that is too random to be the actual Rapture. Leftover is the vast majority of society; they’ve lost loved ones and, equally profound, their systems of belief. There is no explanation for the disappearances and so the religious and scientific communities shatter into sects of kooks and crazies.

Damon Lindelof and Tom Perrotta, showrunner and author of the source text respectively, ground these grand themes in the details of their characters’ coping mechanisms. Matt Jamison, a minister, clings ever faster to his faith. Deserted by his congregation, his church bankrupt and repossessed, his wife hit by a car and comatose, Jamison is tried like few others but does not despair of God’s plan for him. Yet this new world does little but punch him in the face. “What’s your favorite book of the Bible?” a stranger asks Jamison. “Job” he responds, and we don’t doubt it.

Nora Durst lost her husband and two children in the disappearances. She clings to the hope that the miracle town of Jarden, Tex. – verified zero departures – will offer protection from her greatest fear: that she somehow caused her loved ones to disappear, and that it will happen again. So she’s susceptible to the suggestion, posed to her in a phone call from a team of scientists, that she is a “lens” who focuses disappearing rays on those close to her. Yet as the phone call continues, the listening Nora loses faith in the scientific team’s diagnosis of the root problem: that she is possessed by the demon Azrael. Click.

Looming over these individual attempts to regain solid mental ground are cult-terrorists the Guilty Remnant, self-styled “living reminders” of the disappearances. The GR, led in the second season by Liv Tyler’s devilish Meg, invade whatever sanctity the leftovers of the old world attempt to create.

They do so most successfully with protagonist Kevin Garvey. Haunted by the ghost of his Season One adversary, the Guilty Remnant’s Patti Levin, Garvey is driven to suicide. Instead of oblivion, he finds himself battling Levin in a surreal purgatory where she is a presidential candidate and he is an international assassin. Or is it all in his head? The strength of “The Leftovers” is this tantalizing tightrope walk between the natural and the supernatural, a feat also accomplished in the novel version of “The Man in the High Castle.”

“The Leftovers” is some of the boldest premium television of the new golden age, posing profound questions about belief and meaning. Is the show an endorsement of religiosity or realism, of the resilience of the human mind or of the utter insanity of most of the people most of the time? It’s all of these things at once, and that’s as accurate a portrayal of reality as is reasonable to expect.

Stephen Benedict Dyson is an associate professor of political science and director of the Humanities House at the University of Connecticut. Follow him on twitter @sbdyson.