Unfortunately for the plan, some of those outside set up the shout, "A Douglas!" prematurely before the whole party had arrived and were ready to rush into the church.

Dickson with his friends at once drew out their arms and attacked the English; but being greatly outnumbered and for a time unsupported, most of them, including their leader, were slain.

Sir James and his followers then fought their way in, and after a desperate fight all the garrison save ten were killed.
The party then proceeded to the castle, which they captured without resistance.

Douglas and his companions partook of the dinner which had been prepared for the garrison; then as much money, weapons, armour, and clothing as they could carry away was taken from the castle.

The whole of the vast stores of provisions were carried into the cellar, the heads struck out of the ale and wine casks, the prisoners were slain and their bodies thrown down into the mass, and the castle was then set on fire.