Doctors Simaya and Sikaar supervised an autopsy on a murdered Hephaestan, which was performed over a two-hour period by Leonard McCoy and Christine Chapel. The autopsy revealed a subcutaneous symbiont at the base of the skull of the victim. Simaya revealed to James T. Kirk, McCoy, and Chapel that the symbionts were implanted in each Hephaestan shortly after birth. He and Sikaar were the only Hephaestans who knew where the symbionts were manufactured.
When a Klingon solider disintegrated a Hephaestan peace officer, Simaya stabbed the soldier with a surgical knife, killing him. Klingon Commander Kagg responded by disintegrating Simaya with a Klingon disruptor. (TOS comic: "All the Infinite Ways")
- The names of Simaya and Sikaar were flipped midway through the story. The Hephaestan who wore spectacles was introduced as Simaya, but Kagg addressed him as Sikaar. The one without spectacles was introduced as Sikaar, but was referred to as Simaya thereafter.