At Inverness, through the action of the Marquis of Huntly and the treachery of his son, Lord Lewis Gordon, Montrose was surprised by General Middleton, but he promptly crossed the river Ness in face of a regiment of cavalry, under Major Bromley, who crossed the river by a ford above the town, while another detachment crossed lower down towards the sea with a view to cut off his retreat. These he succeeded in beating back with a trifling loss on either side, whereupon he marched unmolested to Kinmylies, and the following morning he went round by Beauly and halted at Fairley, where slight marks of field works are still to be seen; and now, for the first time, he found himself in the territories of the Mackenzies, accompanied by Seaforth in person. Montrose, here finding himself in a level country, with an army mainly composed of raw levies newly raised by Seaforth among his own people, and taught by their chief's vacillating conduct and example to have little interest or enthusiasm in either cause, did not consider it prudent to engage Middleton, who pursued him with a disciplined force, including a considerable following of cavalry, ready to fight with every advantage on his side in a level country. He therefore moved rapidly up through the valley of Strathglass, crossed to Loch-Ness, and passed through Stratherrick in the direction of the river Spey. Meanwhile Middleton advanced to Fortrose and laid siege to the castle, which was at the time under the charge of Lady Seaforth. She surrendered after a siege of four days; and having removed a considerable quantity of stores and ammunition, sent by Queen Henrietta for the use of Montrose on his arrival there, Middleton gave the Countess, whom he treated with the greatest civility and respect, possession of the stronghold.