For decades, the universe's ledger of ordinary matter refused to balance — roughly half of the atoms that theory predicted simply could not be found. Now, a team of astronomers has used 69 fast radio bursts as cosmic flashlights, illuminating the vast dark spaces between galaxies and revealing that most of the missing matter has been there all along, hiding as an almost impossibly thin ionized gas. It is a reminder that absence in science is rarely true emptiness — more often, it is a question waiting for the right instrument.