  In this letter, we study in detail the evolution of the post-flare loops on
2005 January 15 that occurred between two consecutive solar eruption events,
both of which generated a fast halo CME and a major flare. The post-flare loop
system, formed after the first CME/flare eruption, evolved rapidly, as
manifested by the unusual accelerating rise motion of the loops. Through
nonlinear force-free field (NLFFF) models, we obtain the magnetic structure
over the active region. It clearly shows that the flux rope below the loops
also kept rising accompanied with increasing twist and length. Finally, the
post-flare magnetic configuration evolved to a state that resulted in the
second CME/flare eruption. This is an event in which the post-flare loops can
re-flare in a short period of $\sim$16 hr following the first CME/flare
eruption. The observed re-flaring at the same location is likely driven by the
rapid evolution of the flux rope caused by the magnetic flux emergence and the
rotation of the sunspot. This observation provides valuable information on
CME/flare models and their prediction.
