midnight
By Lord Grey 's advice , sentries were posted outside the walls , from nightfall till daybreak , to prevent any risk of surprise by Glendower , whose spies might take him word that the main body of the assailants had left . One of the great halls had been left untouched , to serve for the use of the garrison ; and as an abundance of victuals were found in the house , and the cellar was well stocked with wines , it was but a short time before the garrison made themselves thoroughly comfortable . As soon as it became dark , twenty men were placed on watch . Oswald , with his party , were to take the third watch , at midnight ; and Mortimer 's men-at-arms the second . The captain of each band was to place the men , at such points as he might select . Alwyn talked the matter over with his nephew . `` It seems to me , '' the former said , `` that there is but a small chance of anyone trying to leave the castle ; and at any rate , if they did so , it would scarcely be over the wall , for a splash in the moat would at once betray them .