In 2259 an Enterprise away team searching the crashed USS Peregrine found survivors infested with Gorn young, and chief engineer Hemmer gave his life to stop them.
The away team arrived on a frozen planet to recover the crashed Peregrine and found that the Gorn had used survivors as hosts for their young. The hatchlings hunted the team through the wreck, and La'an Noonien-Singh's experience with the Gorn proved vital.
Hemmer learned he had been infected and would soon become a host himself. Rather than put his crewmates at risk, the Aenar engineer took his own life, and the Enterprise crew mourned one of its most respected officers.