but as they hurried after her , mind-calling her to stop and reconsider , and beg the circle for mercy ( knowing of course that nothing could save her if bloody gorfen never returned , as was most likely to happen ) , suddenly there appeared in the dark red distance a wisp of shimmering stuff that whirled and thickened , sinuously slithering towards tulandas white form , as if conscious of her presence and then , fast as a beast of prey , the mist leapt high and pounced upon her , swallowing her up along with the sound of her final scream .