Dark filament A joining two filament-strends B and C showed an interesting activity of repeated appearance and disappearance during a three-ribbon flare of importance1b at F, starting around 0257 UT.Another sub-flare F1 initiated at 0307 UT.Following these two flares, exactaly at the location of the filament A, an impulsive 2b flare was subsequently triggered (maximum at 0547 UT). After the flash phase, a fast moving dark surge 'S' occured at 0549 UT, lasting about 20 minutes,as seen in the H-alpha line center. The active filament A reappeared after the decay of the impulsive flare (0612 UT frame).