Greetings and salutations,
I ran a one shot based on an "Outer Limits" episode. I cannot recall the name but the premise is as follows.
The Earth is at war with an alien species and the government/military have come up with a plan to end the war. Or at the very least, hurt the aliens so bad, they would seek peace.
The characters have been picked to fulfill the obligations of this mission. Shortly after launch, they are rendered unconscious and wake up in a room in an enemy prison.
This is where it gets interesting. Each character is taken in turn and "questioned" by the aliens. Then the accusations start and the last person the aliens question is the specialist needed to activate the world destroying bomb. The aliens question the specialist intensely. In the episode, the specialist lied so she could gain access to the bomb and activated it. The countdown sh set was for ten to fifteen minutes.
Here's the twist. It was actually a training sim for the characters, but they do not know it is a training sim. As far as they are concerned, they are prisoners of war. The military wanted to make sure that the people it had chosen would be committed to following through mentally and physically.
While the characters are in their room, the military is listening to them. After the military is satisfied that the characters are capable of fulfilling the mission, the back wall opens to reveal a command center. Their commanders tell them of the "experiment" and its purpose. That is when the specialist tells everyone that the bomb has been activated.
In the episode, there was no way to turn off the bomb once activated and there was no way of evacuating the planet.
Good-bye Terra! Thank you for playing!