This is a computer simulation of methane, also known as natural gas, escaping from a methane hydrate. Many of these methane hydrate subunits combine to form a chunk of ice that burns, and this simulation shows how methane can get out without collapsing the entire structure. Red-and-silver water molecules form a cage around two blue-and-silver methane molecules. Two methane molecules are too tight a fit, so a low-energy hydrogen bond -- the red dotted lines -- between two water molecules breaks. This allows the water molecule to swing open like a gate as the methane makes a dash for it. The water molecule swings back into place, the hydrogen bond re-forms, and the methane hydrate remains stable.