“Armageddon Game” is episode thirteen of season two of Star Trek: Deep Space Nine.
Chief O’Brien and Doctor Bashir are away from the station, helping two sides destroy a biogenic weapon created by them both during a war, known as Harvesters. Both the weapons and the knowledge of how to create them are being destroyed.
They are destroying the final batch when armed men belonging to one of the sides burst in and kill everyone. Bashir and O’Brien manage to survive, and beam down to the planet they are orbiting, one whose entire population was killed by Harvesters, so it’s pretty much abandoned. O’Brien was also infected with the Harvesters during the attack.
Back on DS9, the ambassadors of the two sides tell Sisko that Bashir and O’Brien are dead – but they say it was caused by a security protocol that was accidentally activated – and they have video evidence to prove it.
Keiko sees something in the video that makes her challenge it, so Sisko and Dax go to find out what happened. Is one of the two sides trying to restart the war?