In this issue, we introduce a new format. To meet reader demand, QRB will augment its long-standing commitment to Reviews with Essays. Essays will be brief, timely commentaries considering one or more of the following: a new idea, a new argument about an old idea, the answer to an outstanding question, a new method, a new interpretation, or a subject otherwise of importance to biophysicists. Whereas Reviews are intellectually rigorous reports that stand as definitive statements on a subject for many years, Essays will seek to apply the same high standard to highlighting a moment in time, to show us where we stand and, so, to infer our trajectory. Essays will appear as deemed appropriate; this inaugural year will be replete with an Essay each quarter. The Board is pleased to announce that our Essayists for 2004 will be Richard Henderson (this issue), Donald Crothers (May), Christopher Miller (August) and Brian Matthews (November).