Thorium is the element aerospace engineer Kirk Sorensen spent a decade at NASA arguing should replace uranium in nuclear power, and this compilation lays out his case at length. It opens with the energy problem facing deep space missions, running through Voyager 1, New Horizons, and the Mars Exploration Rovers to show how solar and battery power fail once a spacecraft gets far enough from the sun, stalling plans like a probe beneath the ice of Jupiter's moon Europa. From there the film pivots to Earth, walking through the Molten Salt Reactor Experiment run at Oak Ridge in the 1960s and the case for a Liquid Fluoride Thorium Reactor as a safer, more efficient alternative to today's water-cooled plants. Footage from outside sources, including Pandora's Promise and clips of Neil deGrasse Tyson, is folded in to make the broader argument for nuclear power. India's thorium reserves and ongoing research get their own segment. Assembled by Gordon McDowell from years of volunteer-shot footage, it is less a single narrative than a sustained pitch for one specific reactor design.