With only her, her mother and the children at home, Vesper was a dangerous time. So Donella had shut the entrance. Yet the Viking attack on the Broch was furious. Their fire had damaged the stout timber entrance, now their axes rained down upon it. So Donella and the children constructed a defensive barrier against the hatch.
She was also worried for her men. They had gone to the hills hunting. If they returned, their anger would boil over. But three against eighteen was bad.
She, her mother, the children, would sooner kill themselves rather than becoming chattels for pagans.
Footnote: The object with chains in the picture, reminded me of slavery and death. Whilst today I have walked in the footsteps of Vikings and Christians around Burnsall.