Ezra Berg is one of four main targets that you need to eliminate. You can use the available Opportunity to do that, although it is not necessary. The most efficient ways to eliminate Rose were described below:
- Kill Ezra Berg one-on-one in the basement (Tongue Tied Opportunity)
- Kill Ezra Berg in an explosion
- Set Ezra Berg on fire
Kill Ezra Berg one-on-one in the basement (Tongue Tied Opportunity)
Your plan is to attack Ezra after he goes to the basement in the main building. The entire procedure consists of several steps and the first one is listening to a conversation between two guards in the south part of the farm (M7.34). You will learn that Ezra has a prisoner in the basement and that he is interrogated with use of home-made chemicals (M7.36).
Your next step is also optional. You can head to a small garage located by the main building (M7.15), which is also the "headquarters" for Ezra. If Berg is inside, patiently wait for him to leave the building. Furthermore, the garage is protected by two enemies. It shouldn't be too hard to get rid of them: wait for them to finish their conversation, make sure that no one is watching you and assault the first soldier. You can make the other solider leave the hut by damaging the fuse box. Hide both bodies and enter the garage. There is the monitoring and basement key.
You can go to the basement but keep in mind that this part of farm is restricted for elite troops and hackers only (make sure to use the right disguise). It's best to access the basement through the door located on the ground floor of the building (M7.32), as it is not protected by any guards.
Once you get to the basement (M7.36) wait till there is only one guard left. Sneak up on him from behind (or distract him with boiler), eliminate him and hide his body (and his weapon!).
You can approach the locked room (M7.32). Press the button to increase the dose and make the prisoner lose consciousness.
Hide in a dark spot and wait for Ezra to come downstairs. Take advantage of the fact that there are no guards with him and kill him as you like (e.g. with a garrote or a silencer). Quickly hide his body as soldiers can appear (an alternative would be to turn of the light, wait for any enemies to come, shoot them and leave the basement).
Kill Ezra Berg in an explosion
The gas container is located in a small garage (M7.15) that Ezra Berg visits from time to time. There are two additional soldiers that you would have to eliminate. Wait for the enemies to finish their conversation, make sure that no one is watching, and attack the first soldier. You can make the other one leave the hut by damaging the fuse box. Hide the bodies and enter the garage. Damage the gas container and wait for Ezra. Careful place yourself behind his back and take the shoot to cause an explosion. Leave the garage immediately.
An alternative way would be to kill Ezra Berg in an explosion of one of the gas lamps located in the back of the main house (M7.25). However, this will be more difficult as you would have to make Ezra (e.g. by throwing object) to come near one of the lamps. Furthermore, they can explode by themselves, so your timing must be perfect.
Set Ezra Berg on fire
Investigate the garden tractor located near the main entrance of the house (M7.21). Create oil leak as soon as you realize that Ezra Berg is heading this way (from the garage or the basement). Move to a location where you can safely take a shoot (silencer). Ezra Berg should stop by the garden tractor for a moment - that's when you should strike. A successful attack will set Ezra Berg on fire.