We have studied the unusual photophysics of a thioketone, thiocoumarin, in n-hexane and in acetonitrile by femtosecond fluorescence up-conversion and transient absorption spectroscopies. The lifetime of the S-2 state is found to be as short as 450 +/- 50 fs in n-hexane and 130 +/- 50 fs in acetonitrile, whereas the S-2 lifetime is about 10 ps. We propose that the fast S-2-state deactivation is governed by a conical intersection point linking the S-2 with S-1 potential energy surfaces. Direct absorption from the S-1 state of thioketones has been observed for the first time.