- Main article: The Orange Box
How to Obtain:Kill an enemy by planting a Hopper Mine.
This can be done in Half-Life 2, Episode One or Episode Two. Use the Zero Point Energy Field Manipulator (Gravity Gun) to pick up a Hopper Mine, then drop the mine which will change it's setting from hostile to friendly then lure an enemy into it, if the enemy dies the achievement will unlock. An ideal area to do this is in Episode Two chapter This Vortal Coil. Plant a Mine, found in the crates, down one of the tunnels and it's almost guaranteed that an Antlion Soldier will die from it..