This is how I got the Silent Threat achievement, I'm sharing the steps and actions I took to get it. I don't think this is the most efficient guide, but it worked for me.

My method to get this achievement is reliant on the map spawn RNG, Interrupt Avoidance chance, and Melee Hit chance and Damage

Priority is to max out Tactical Movement to 50 (max distance travel and Interrupt Avoidance chance) and Close Combat to at least 25 (for the increased hit chance and 25% free action chance).


If you need XP, Farm Custom Missions, my farming method was Hold Position in Africa Town I, this mission would take less than 5 minutes and would reward me around 85 XP and 300 Credits. The Credits can be exchange for XP with the Advanced Training item (200 Creds for 100 XP).

Unfortunately there is an inconsistency in the screenshots, because I didn't think I would be able to get the achievement, and thus was unprepared to record the early half of my run.

The mission I ran to get this achievement was Custom Mission - Escape and Evasion on Dam Entrance.

<start of image inconsistency>

The starting positions are RNG, and you would need to be lucky to get a rotation similar to this. Note that I will be assigning specific labels to the character such that it would make explaining things much easier. I found this to be the bread winning position as I only needed to kill 3 guards (G1, G2, and G3) in melee.

Have S4 move towards the gates, while hugging the car and walls.

Have S3 move all the way to the edge of the wall.

Have S1 move to G1 and kill him in melee. Do the same with S2 for G2.

<end of image inconsistency>


Now here comes the scariest RNG part of this run, have S3 hug the [blue tarpoline?] and get ready to move into melee and kill G3, make sure you end your turn when you reach the tarp, as moving to the guard will take 1 AP and hitting in melee will cost another. Now move to melee G3, which will cause him to spot and attempt to interrupt S3, this is where the 40% Interrupt Avoidance chance will come into play, as you will need to avoid the interrupt to kill him without having him shoot (which will invalidate the run).

Once the hardest part is over, its just a matter of cautiously moving your S1 - S4 towards the gate while hugging the walls, be sure to hug the walls to prevent any of the guards in the guard house from spotting you. I was lucky in my run as I only spotted one guard in the guard house, other runs may differ, so please adjust accordingly.

Just get everyone to the gates, but be sure to hug the walls by the gate just to be safe.

Hopefully everything goes well and you should be able to clear the mission, get the achievement, and I get to never think about this game ever again.

Hopefully this guide will be of help to someone.