Martha Krebs, director of the Office of Science at the US Department of Energy, has resigned. The office has an annual budget of $3 bn and runs some of the largest physics laboratories in the US, including the Argonne, Brookhaven, Oak Ridge and Lawrence Berkeley national labs. It also operates the US's two premier particle physics labs - Fermilab and the Stanford Linear Accelerator Center. Krebs, who was appointed in 1993, will leave in December. Bill Richardson, head of the DOE, said that "her expertise, energy, vision, professionalism, and her leadership will sorely be missed."