OPTIONAL OBJECTIVE- use the berserk darts on two brutes
Close to the entrance to the mission zone, at the first bell, you will find a patrol of two brutes. Shoot at either of them, which will case the all of the nearby soldiers to react and launch at him. Use the commotion to run up to the alarm and deactivate it. After that, jump immediately into the bushes. As soon as berserk wears off, and there will still be many guards remaining, shoot one more. If the fight has been fruitful and there is only one or two soldiers remaining, keep the second dart for later, and finish off the survivors in a more traditional way.
OPTIONAL OBJECTIVE- use the sleep darts on two gunners
Right next to the first alarm, there is a tower. Put the guard on the tower to sleep. You do not need to climb up to finish him off. Your old-new ally should do that for you.
A bit ahead, there is another alarm, and another tower, with a gunner, behind it. Put the gunner to sleep to complete the bonus objective. Deactivate the bell in a more standard way, after you cut through the soldiers. They are the regular guards so, they should be no problem. Implement the old strategy and wait for the attack, after which you press the counter-attack, and then the attack to finish off the enemy. If necessary, use the smoke bomb to your aid. Also, watch out for the soldiers who want to activate the alarm. You will be able to recognize them by the red bell above their heads. Kill them in the first place, preferably by using the pistol. Once you deactivate the alarm, run for the last one.
Another tower with a gunner and another group of soldiers around the alarm, including one brute. Put the gunner to sleep and use a berserk dart on the brute. Then allow the soldiers to fight among themselves. At the same time, deal with the alarm. Once all of them are disabled, run to the gate to meet up with the Kidd girl to complete the first part of the mission
Find and kill Laurens Prins
In front of the residence, you will find a brute patrolling the area. Shoot him with a berserk dart, or whistle, and kill him in the bushes, if you are out of darts. Once the guards start fighting among themselves, climb onto the rooftop. Ignore the regular soldiers, even if you are spotted.
On the rooftop, there are two gunners, on the left and on the right. Run along the left wing and eliminate the musketeer on flight. Then, dive headlong into the cart with hay below.
Prins is in the garden house in the middle of the garden. From the cart that you are in, it is a short way off. Sneak up and get him down with running assassinate, by running inside through the entrance on the left. This will initiate a cutscene.
Escape and hide
After you regain control over the character, look to the right. You will notice there a tipped cart from the screenshot. Run up onto the cart and onto the tree. Go ahead by jumping from a tree onto another, until you return onto the ground near the wall.
Here, you will find a fallen tree leaning against the wall. Run onto the tree and you will find a cart with hay at the end of the path, where you can wait until the search for you, around the residence, stops.
The path ahead is difficult and full of soldiers. If you want to, you can try moving around silently, by using the trees and thickets until you make it put. Still, it is faster to ...run. Climb out of the cart and start running ahead towards the green point and ignore everything. It may happen that you will be knocked down several times, by the guards. In such a situation, do not worry about anything and definitely do not fight. Simply, get up and continue running ahead.
Once you reach the mill, run inside from the right and turn left to run around the mill. The soldiers should be trailing behind you, just like on the Benny Hill Show.
After you run a full circle, run out at the other side and jump into the hay cart, just like in the screenshot. While behind the mill's wall, you should be able to lose them all. If necessary, take one more circle around the mill and make sure that you left all of them behind. Wait in the cart until the search is cancelled and approach the pirate to complete the mission.