It is shown that the direct precursor for the formation of a photochrome in Schiff bases is a "twisted" geometry S-1 state of a keto tautomer in which the O . . .N-H hydrogen bond is broken. In photochromic Schiff bases this state is close in energy to the pi pi* state of the cis-ketone obtained from the initially optically excited enol species by an ultrafast excited-state proton transfer, in particular, in N-salicylidene-alpha -methylbenzylamine (SMB), it lies within 1 kcal/mol from the pi pi* state of cis-ketone and similar to 16 kcal/mol below the initial pi pi* state of enol. The excited-state proton transfer in SMB is predicted to take similar to 15 fs and to be nearly barrierless. It is also shown that the initial pi pi* state of enol can decay via competing route to a twisted geometry n(N)pi* state of enol with the energy similar to 20 kcal/mol below that state.