Last seen in the episode 'The Crystals', the Optical Engram Imager (OEI) is an impossibly sophisticated machine that is used to probe the mind and visualise distant memories on a monitor. When a war crimes prosecutor accuses Buck of being directly responsible for the holocaust that almost wiped out the human race, his only hope is to pop on the OEI and trawl his subconscious for any evidence that might prove his innocence.
Totally unlike any of the episodes that have preceded it, Testimony of a Traitor is a surprisingly gripping tale that manages to be intriguing, suspenseful, and exciting, as well as rather enlightening, by showing some of the events that led up to the destruction of Earth's civilisation in the 20th Century. Not only are viewers treated to the tense courtroom drama of Buck's interrogation, but we also get to enjoy a space battle, some welcome action on Earth, Hawk deploying his spacecraft's talons (for the first time since the beginning of season two), and Erin Gray back in her sexy Spandex outfit.
This episode also sees lucky old Buck finally getting a full-on juicy lip-lock from Wilma: something worth waiting 500 years for!