An Enterprise lieutenant responsible for re-energising the ship's dilithium crystals in 2267, who is attacked when Lazarus steals them to power his own vessel.
Lieutenant Charlene Masters appears in the first-season episode The Alternative Factor. She runs the section of engineering where the dilithium crystals are recharged, and reports to Kirk on their condition after a strange effect drains much of the ship's power.
The wild-eyed traveller Lazarus demands the crystals to hunt down his enemy, and Kirk refuses him. Soon afterwards Masters and her assistant are overpowered at their post and two crystals are taken. Later a fire is started in her section as a diversion, and she is brought out suffering from the smoke while more crystals disappear.
Masters was played by Janet MacLachlan. Her first name comes from the script and is not spoken on screen.