John B. Watkins was an Engineer, Grade 4 who served aboard the USS Enterprise under Captain James T. Kirk. In 2268, Watkins served as chief engineer Montgomery Scott's assistant, when he was ordered to check the bypass valve of the matter-antimatter reaction chamber. While carrying out his orders, he was approached by the mysterious entity known as Losira, who questioned him about the operation of the ship. Suspicious, Watkins gave the woman incorrect answers and called out to Scotty that there was an intruder on board. Unfortunately, he was killed by Losira's cellular disruption ability before he could be saved. (TOS: "That Which Survives" )