Physicist Jim Al-Khalili sets out to explain the force that governs everything from a dropped apple to the orbits of planets. He traces the idea from Newton's laws through Einstein's general relativity, using demonstrations, historical reenactments, and interviews with working physicists to show how each theory changed what gravity actually is, not just how it behaves. Al-Khalili visits labs where researchers test gravity's limits, from pendulum experiments echoing Newton's own methods to modern instruments built to detect gravitational waves rippling through spacetime. The film treats gravity as an unfinished problem as much as a solved one, spending real time on where Einstein's equations break down, at black holes and in the earliest moments of the universe, and on physicists still hunting for a theory that unites gravity with quantum mechanics. Al-Khalili's own enthusiasm carries the film through the harder physics, and the demonstrations keep the abstract math tied to something you can watch happen on screen, whether it's a falling object or a laser beam bent by mass.