You need to listen to the furious spirit's sentences and run to the corresponding memory item and click it. Then you can damage her by your attacks. If you choose the wrong item you get severe damage (up to 50% Health) and may die choosing wrong the second time. Check the chat for the following message "You elicit the correct memory!"
The debuff cues are:
Letter: How could I not have seen what he was doing? Was I so blind that I allowed him to tear us apart?( -25, 1, -15 ) /waypoint -25.29, 0.81, -15.08.
Scroll: I stood against our enemies dutifully, and this is my fate? How could he condemn me to this?( -11, 11, 15 ) /waypoint -11.18, 10.50, 14.57
Book: He was my heart – why would he do this to me?( -22, 11, -31 ) /waypoint -22.36, 10.50, -30.69.
Rose: How could he give her his favor? Were the gifts he granted me naught but false?( 39, 11, -16 ) /waypoint 38.84, 10.50, -15.98
Dagger: Are you here to stab me from the shadows as they did? Then come, and meet their same fate.( -7, -0, -2 ) /waypoint -7.33, -0.05, -2.01.
After using all five memory items, the furious spirit appears in the downstairs room, where she was at the beginning. Destroy all the bottles in the room; the bottles release spirits that damage the furious spirit.
After defeating her she calmes down and turns back into a forlorn apparition( 52, -0, -2 ) /waypoint 52.18, -0.18, -1.63.
Click on your listless body, then the front door, in order to leave the zone.
This article refers to events, personae and activities only present in-game during the annual Nights of the Dead festivities, which come to Norrath each year from (roughly) mid- to late-October through to early- to mid-November.