on the second last level. There are lots of hints.
First of all listen to all the logs in the room with the hunters they are really interesting.
Also you can smash the cameras throughout the level.
In the big room with the terminal where you get the mantis there is a log where a guy says he has stashed something in something like area B2. I think we know where we need to go! I didn’t have much time but somebody needs to listen to this with subtitles. This is a blatant hint!