Molecules with many spin-crossover sites could be used as multistepped molecular switches. The CNbridged molecular square [Fe II 4 (m-CN) 4 (bpy) 4 (tpa) 4 ](PF 6 ) 4 (bpy = 2,2'-bipyridine; tpa = tris(2-pyridylmethyl)amine), a Prussian blue analogue, undergoes thermally induced, two-step spin conversion. For more information, see the Communication by H. Oshio and co-workers on the following pages.