Commander Toreth (Carolyn Seymour) was the commander of the warbird IRW Khazara and was a capable and professional commander who had previously received the Sotarek Citation for winning a decisive victory over the Klingons. She hated the Tal Shiar (the elite intelligence agency of the Romulan Star Empire) who had been responsible for the murder of her father.
In the Star Trek: The Next Generation episode ‘Face of the Enemy’ Deanna Troi wakes up one morning to discover she’s a Romulan aboard a Romulan warship and sharing it uncomfortably with Commander Toreth.
It turns out to be one of Spock’s cunning plans: Deanna Troi’s been kidnapped and surgically altered to become ‘Major Rakal’, an officer of the Tal Shiar, to take part in a secret mission – implausible but at least it gave Marina the chance to try out a few new expressions (and even to lose her rag).
It is probable that this was the role that Joanne Linville was offered when she was asked to come out of retirement to reprise her role as a Romulan commander. When she was unavailable the production staff created a new character of Toreth for Carolyn Seymour in the belief that Subcommander Taris, played by her in a previous episode, had been killed.
Michael Westmore was the makeup designer and supervisor on Star Trek: The Next Generation.