Boorswell, the little marshy estate to the north has been ignored by the other Lords, because there's little productive land there. Now it is infested with gong and rats, who also spread into your estate. Do something about it.
If you've been doing what the other Lords did and ignored this estate so far, you might be caught in a bad situation. Since the Outlaws have been attacking this estate repeatedly (if you didn't do anything against it) the lack of food will have been bad for the inhabitants' mood. If your popularity is significantly below 50 at the start already, you may actually be out of a chance to win this mission.
First of all, turn down the game speed or better yet, pause it. Looking into your stockpile, you'll notice that all your wood has vanished. Instead of waiting for some, buy it. You'll need about 500 to 600 units and you should have the money to do so.
Now place gongpits near the Granary and the Stockpile in both Boorswell and Harbury. If you have more than one stockpile, place one gong pit for each stockpile. In harbury place additional gong pits near the Armoury, the Inn and the fletchers/pole turners.
Now place 3 falconers posts in each of the two estates, spreading them out evenly. Now sit back and wait for the victory message.
Alternative ApproachEditIf Boorswell had been taken care of before, this mission should not last longer than a minute or two on normal game speed. However, there is a strategy that may prove fast and uses about a third of the stock mentioned above.
Pause the game. Buy in some apples and 200 wood for gong pits and falconers. Erect all of them in Boorswell only: if you are fast, gong and rats would not expand into your home estate. Additional posts may be erected at home though, but it is not a must. Activate a carter's post to send apples (not much) to Boorswell and send a good sized army to deflect outlaw harassments.
Whill still on pause, locate every gong pile in Boorswell and try to place saw pits on each of them: if you build on a gong pile, the gong vanishes instead of being placed a bit away, unlike troops or peasants. Unpause the game. Falconers will take their posts and hunt rats, but rats may even leave Boorswell running to another estates, leaving the estate clean. This way victory can be triggered very early without too much trouble.