USA’s “Colony” (premiering Thursday) is a sci-fi family drama that is surprisingly more than the sum of its tropes, which are many. There’s no keeping track of how many times Earth has been invaded and its inhabitants subjugated by fascist aliens, especially on TV series and miniseries, but it’s quite a few.

Here, “Lost” alum Josh Holloway plays Will, a father and husband struggling to get by in a walled-off, heavily surveilled Los Angeles, which a year or so back was taken over by — well, by something sinister and powerful enough to remove all of the automobiles, which, if nothing else, finally compelled more people to ride bicycles.

Are we now ruled by aliens? Did President Trump go too far with his dreams of a walled-off electorate? One thing’s for sure: The inhabitants all live in mortal fear of being caught in any sort of act of crime or disobedience, lest they be shipped off to “the Factory,” which doesn’t sound good. “Colony” is intentionally stubborn on details — a creative choice in today’s television, where pilot episodes tend to overstate the premise.

Will and his wife, Katie (Sarah Wayne Callies, the dearly departed Lori from “The Walking Dead”) have three children, but only two live with them. The third, a 12-year-old son, is for some reason trapped on the other side of the wall. Will attempts a covert trip to find him, but he’s caught and arrested.

Whatever entity has taken over L.A. has the cooperation of a group of opportunistic humans who form a proxy power structure that has secured a better lifestyle in return for enforcing obedience. A leader named Snyder (Peter Jacobson) has discovered Will’s past as an Army intelligence officer and offers an ultimatum: Will can either infiltrate and spy on a a growing resistance movement or he and his family can prepare themselves for a permanent trip to the Factory.

Sarah Wayne Callies as Katie Bowman, Josh Holloway as Will Bowman and Isabella Crovetti-Camp as Grace Sullivan on the USA drama "Colony." (USA Network/Isabella Vosmikova/USA Network)

“Colony” is co-created by Carlton Cuse, who, as one of the minds behind “Lost,” is no stranger to peeling his stories one layer at a time; the first episode leaves a viewer a heap of unanswered questions and even a sense of confusion about what this show intends to be. But what’s also immediately apparent is a care for setting and character-building. “Colony” probably won’t work for the passionate sci-fi fan who demands the blueprints up front, but it might appeal to those who generally avoid the genre.

More notably, “Colony” possesses a quality that I’ve always felt was missing (or underplayed) from these dystopian, world-destroying, alien-invasion soap operas: It’s sad.

Next to fear, sadness would of course be the overwhelming shared emotion if some otherworldly force disrupted our social order. We'd cry and cry and cry, not only for what we’d lost but also the losses we sense are yet to come. “The Walking Dead” has explored this to some extent, but still usually favors intensity over psychology. Aided by a strong script that seems to recognize this, Holloway and Callies come across as characters who know the real depth of a doomed world.

Colony (one hour) premieres Thursday at 10 p.m. on USA.