Preston Fight by William H. Ainsworth

Somewhat late in the evening, Captain Douglas, who, it may be remembered, had the command of one of the Northumbrian regiments, informed General Forster that a spy had been arrested, but the general was so much engrossed by Mrs. Scarisbrick that he paid no attention to the information. Captain Douglas then spoke to Brigadier Mackintosh, who at once went with him to a small room where the man was detained.

Meantime, the spy had been recognised as Ralph Fairbrother, for whose capture a reward had been offered, and who was supposed to have gone to General Carpenter at Newcastle. On being searched a letter was found on him addressed to General Wills, giving particulars of the exact state of the forces, and making some remarks on Forster's incompetency. The letter bore no signature, but was in a female hand. A few lines, traced in pencil, had evidently been added at the ball, and this important postscript recommended an immediate attack of the town, stating that it must be successful, since Forster was unprepared.