Oil, coal and other fuels rich in hydrocarbon come from ancient biological matter, according to conventional wisdom. Now scientists find evidence for an inorganic origin of hydrocarbons—specifically, at Lost City, a collection of natural rock towers atop a submerged mountain in the Atlantic Ocean. The ocean floor around Lost City is full of vents that go all the way to the mantle, and researchers at the Woods Hole Oceanographic Institution and their colleagues have found high concentrations of hydrocarbons in the fluid seeping from these cracks. The hydrocarbons do not carry the isotopic signature linked with life—instead the scientists conjecture that they were produced when carbon from mantle rock interacted with seawater vented from Lost City, which is loaded with hydrogen gas. The researchers suggest that many such fields exist and could have produced building blocks for life. Delve into the February 1 Science for the details.