Atmospheric temperance field
From Tardis Wiki, the free Doctor Who reference
Missy altered the atmospheric temperance field in the Sunken Desert to alter the brainwaves of all visitors, making them believe they were in the middle of a battlefield. She also "conveniently" left a small arsenal, providing weapons for the sudden onset of war. In fact, they had all come to have picnics and were complete strangers.
Around two days in, the Lumiat used a paradigm nebuliser to reverse what Missy had done. The visitors were horrified by their actions, once they remembered the truth. (AUDIO: The Lumiat)
