Bend it, shape it, remember it: Shape-memory alloys have the useful property of returning to their original shape after being greatly deformed. This process depends on the collective behavior of many small mineral grains in the metal. Using three-dimensional x-ray diffraction, Sedmák et al. tracked over 15,000 grains in a nickel-titanium shape-memory alloy as it moved through this transformation, thus linking microscopic changes to the bulk deformation. Science , this issue p. 559