Well, the Fortress has finally fallen.
The Goblins, unable to get inside my walls, enlisted the aid of a tribe of Raven people, who quite handily flew right over them.
They didn't stay long, but the casualties they inflicted were enough to trigger a long, slow cycle of recrimination and death. One of those killed by the Raven people was the expedition leader, who had an almost supernatural gift for cheering up and calming down angry or depressed dwarves. With him gone, recriminations flew over who was responsible, and matters weren't helped by the death (from infection - the fighting polluted both wells) of the mother of one of my major clans.
As the population dwindled the unfinished towers of the surface fort became home to increasing numbers of Raven People, drawn by the unclaimed remains of Dwarf, Elf, Goblin and Yak around the fort.
Eventually, the long awaited Caravan from the Mountainhome arrived. Every able bodied dwarf in the fortress reported for duty, clad in a motley of whatever equipment they could scavenge.
We Opened the gates, and went forth.
It was close. Of the innumerable horde of Goblins, perhaps a dozen survived the fight, and none of them uninjured. The Merchant guards fought bravely, as did every dwarf in the fortress. But it was not to be.
Beneath the fort, the crippled cook Momul heard the victory chants of the Goblins approach, and pulled the Lever, comforting the few remaining children as the water streamed into the chambers and the shouts of the Goblins turned from victory to panic.
Losing is fun, bastards.
So now GraveAbbey is broken, and only the cries of the Raven people remain around its towers.