Dartmoor is one of the more intriguing locations of Hitman 3. At first glance, it's a sniper's dream come true. There is an unobstructed view of the manor from everywhere around it. The manor itself has plenty of windows. And the security detail on the perimeter is sparse at best. If that sounds too good to be true, it is.
Your target, Alexa Carlisle, is all too aware of her precarious position and she's committed to never get anywhere close to the windows and balconies unless you can somehow lure her out. But luring her out of means luring her entire entourage out and that means witnesses and collateral damage. Very well, then. If the target won't go to the sniper, let the sniper go to the target.
Loadout
Does all the poison stand out on this list? Good. The deal is that you have three enforcers to contend with, so you'll need three kinds of poison. The Sieker 1 is highly recommended as it has two shots, so it can take care of two out of the three. After that, either an emetic grenade, an emetic syringe, or both will do nicely.
Also, starting in Zachary's bedroom as the private investigator will get you the closest to where you need to be and let you freely wander in the first and last part of this guide without any need for sneaking around.
Lastly, don't forget to bring your favorite suppressed sniper rifle and stash it in the hallway.
Taking Out The First Enforcer
First thing's first, this is a sniper assassin challenge, after all, so let's go get your suitcase with the rifle in it. You'll find it on the same floor as your starting location and just down the hall past some stairs.
Now it's time to go up halfway up those stairs you just passed. The first of the three enforcers you need to remove is standing guard at the top. When nobody is looking, shoot him with the Sieker 1.
Follow him as he heads down the stairs to the restroom. Remember not to kill him or anyone else as he is throwing up; sniper assassin requires no fatalities other than the target. Knock him out with the suitcase and stuff him in the container in this bathroom. Take his costume and head back upstairs.
Taking Out The Second Enforcer
The second enforcer is standing in the middle of the hallway. Like the first one, you'll want to give him a round from your Sieker 1 to make him sick. However, unlike the first guard, he'll be going to a different restroom. Follow him in but don't bop him just yet.
This restroom was apparently designed by someone who didn't care for their privacy all that much. A huge glass door does nothing to block the line of sight here. And, unfortunately, up to two servants, Alexa Carlisle, and her bodyguard can all be in the adjoining room at the same time.
If Alexa and her bodyguard are in the room, wait for them to leave. The maid also goes back and forth. The other housekeeper stays in the room, but he faces away long enough for you to knock enforcer number two out and place his body in the dresser at the far end of this bathroom. As you drag him, go behind the bathtub to minimize the chances of being spotted.
Taking Out The Third Enforcer
The third enforcer is the bodyguard tailing Alexa Carlisle wherever she goes. Whether to use the emetic syringe or grenade on the next target is a matter of preference.
If you elect to use the grenade, know that holding it is not illegal but throwing it is, and make sure you don't hit Alexa Carlisle with it. You will want her to continue her routine. If you elect to use the syringe, just make sure to choose a moment when no one else can see you.
After poisoning this guard, follow him to the restroom and repeat the exact same process as with enforcer number two.
Taking Out Alexa Carlisle
It can be tempting to poison Alexa to get her all alone, but the cabinet is stuffed with bodies and even a silenced sniper rifle will draw attention because of the body falling and the bullet striking.
So you'll need to ambush her. Alexa is regularly alone with her thoughts in the private room (labeled on the map) but the area is a trespassing zone. Thankfully, because you've disposed of the bodyguard, you can lurk just outside and wait for her to enter.
When she does enter, wait for her to sit down. Then open the door, close the door behind you, take your rifle out of your briefcase, and go for the easiest headshot you've ever had in your life.
Afterward, hide her body in the secret room behind the wall she is staring at. There is a button to press that will allow you to sneak in there.
Grab The Files And Leave
Exit from the same door that you entered and go to Alexa Carlisle's chair. You'll see a button that's illegal to press. If you squat down when you push the button, you shouldn't have any problems.
Pressing this button will reveal a safe. The code is 1975 and after you type it in, grab the files. Now you just need to find a safe exit.
There are a few enforcers to your current disguise, so if you want to be absolutely safe, change back into the detective's outfit in the restroom on the floor beneath you. If you do this, just remember to drop your sniper rifle or hide it in the briefcase first.
After that, you're home free! Take any exit you'd like and enjoy a nice cup of earl grey tea, 47.