We present a theoretical study of the multistate dynamics of the Ag-3(-)/Ag-3/Ag-3(+) system on the time scale of nuclear motion, as explored by femtosecond pump-probe negative ion-to neutral-to positive ion (NENEPO) spectroscopy. The dynamics of the Ag-3 cluster initiated from its linear transition state involves configurational relaxation, intracluster collision, and onset of IVR, resonant and dissipative IVR and vibrational equilibration, whose time scales were determined. Our analysis reveals that theory is essential for the elucidation of the rich dynamic information regarding geometrical change, completion of IVR, and vibrational coherence effects in the NENEPO femtosecond signals.