On the surface of a living cell at any given time, hundreds of tiny bubbles are popping into existence, surrounding and incorporating proteins, hormones, fats, and the occasional bacteria or virus. But until now the details of this activity were inferred – you couldn’t actually see it. The problem wasn’t just that the structures taking part in this bustling activity are too small, but that our bodies work on an invisibly fast time scale—important changes are taking place over fractions of a second.