The parley was short, and the followers of Sir Cahir, rushing in to the tower, fell on the sleeping garrison, slaughtered them in their beds, and then made their way to an upper apartment where Lady Harte's brother, recently come from England, was fast asleep.

Fearing that he might get a bloody blanket for his shroud, Lady Harte followed them into the room, and implored the young man to offer no resistance to the Irish, who broke open trunks, presses and other furniture, and seized whatever valuables they could clutch.

Her thoughtfulness saved the lives of her children and her brother; for as soon as Sir Cahir had armed his followers with matchlocks and powder out of the magazine, he left a small detachment to garrison Culmore, and then marched rapidly on Derry, where he arrived about two o'clock in the morning.

Totally unprepared for such an irruption, the townsfolk were roused from their sleep by the bagpipes and war-shout of the Clan O'Dogherty, who rushed into the streets, and made their way to Paulet's house, where Sir Cahir, still smarting under the indignity of the angry blow, satisfied his vow of vengeance by causing that unhappy gentleman to be hacked to death with the pikes and skeines of Owen O'Dogherty and others of his kindred.
After plundering the houses of the more opulent inhabitants, seizing such arms as they could find, and reducing the young town to a heap of ashes, Sir Cahir led his followers to the palace of Montgomery the bishop, who fortunately for himself was then absent in Dublin.

Not finding him, they captured his wife, and sent her, under escort, to Burt Castle, whither Lady O'Dogherty, her sister-in-law and infant daughter, had gone without warders for their protection.