This article contains spoilers. Read at your own risk!
It might spoil your gaming experience when first playing the related games.
The bomb is first introduced in Opposing Force's fifth chapter, Friendly Fire, where it can be seen in the back of a truck, guarded by two Black Ops assassins, and near the rocket from which it was removed, in an Ordinance Storage Facility connected to Sector E Materials Transport.
Later in the game, in the thirteenth chapter, "The Package", Shephard discovers two other Black Ops assassins setting up the bomb in an underground parking lot under the large Ordinance Storage Facility and connected to Sector E Materials Transport. After killing the assassins, he deactivates it. Afterwards, he proceeds to a nearby room with a view on the truck, and witnesses the G-Man reactivating it. He cannot return to the truck, making the destruction of Black Mesa inevitable.
The bomb explodes when Shephard is detained by the G-Man aboard an Osprey at the end of the game, when a white flash covers the screen while the G-Man makes a slight pause in his monologue.
The following instructions are written inside the bomb's lid:
- MANUAL INSTRUCTIONS FOR A:
- MARK IV THERMONUCLEAR DEVICE
This device carries a GRADE C plutonium control detonator.
With this device an approximate safe distance of
55 kilometers is recommended.
- Indispose the gravatronic rev limiter to 11.
- Rotate red knob to the on position.
- Press button labeled B.
Behind the scenes
Although subsequent games tend to disregard the Gearbox expansions' storyline, series' writer Marc Laidlaw has confirmed that the destruction of the Black Mesa Research Facility at the end of Opposing Force is canon.
List of appearances
- Half-Life: Opposing Force (First appearance)