When Edward found out about Harclay's treason, he issued an order for the earl's arrest. As Harclay attempted to garner support for his cause, the king began to fortify the northern castles. The stalemate lasted until 25 February, when Sir Anthony Lucy arrested the earl at Carlisle Castle. Lucy, who acted with only a small force, was clearly trusted by Harclay, so the arrest must have been conducted as a surprise manoeuvre. The enmity between Lucy and Harclay could stem from a dispute over the honour of Papcastle. In 1322, Harclay had also briefly disseised Lucy of his lands after the 1322 rebellion, even though Lucy had taken no part in that event.