If an image is worth a thousand words, and a video is 30 frames per second, then these movies of a developing zebrafish must be worth millions. I could not conceive now of a course in embryogenesis that did not include these fascinating and wholistic perspectives on the developing organism. What drives those pulses of development, those three- to four-cell cabals, those intricate dances of the somites? Is it all gradients and cell-cell interactions? Or is there a master control program?