Danny Hillis wants to build a clock that keeps time for ten thousand years, and this film follows the inventors and engineers trying to make that literal. Hillis, a computer scientist who helped pioneer parallel computing, founded the Long Now Foundation on the idea that civilization thinks in cycles too short for its own good, and the clock is his attempt to build an object that forces longer thinking. Cameras follow the team into a Texas mountain where the mechanism is being carved into the rock, working through problems no clockmaker has faced before: materials that won't corrode in ten millennia, a design that stays accurate without electricity, a mechanism that can be wound by visitors centuries from now who have no instructions left to read. Interviews with Hillis and his collaborators lay out the philosophy behind the project as much as the engineering, including the funding push from Jeff Bezos that made construction possible. The clock isn't finished, and the film treats that unfinished state as the point.