From the Castle, the team witnesses one of Zarkon's ships being shot down by a persuing group of the same. Rushing to the crash site, Hunk finds a young, injured girl with one of Zarkon's slave tatoos on her arm. Determining that she's alive, he takes her back to the Castle to get medical help.
Twila tells a tale of how she and her brother were captured by Zarkon but she managed to escape.
Later, Keith muses aloud about how her story doesn't seem to add up but Hunk gets really defensive.
Turns out, Keith was right. During the night, Twila sneaks down into one of the rooms in the castle where a lot of machinery and computers that run the place is located. Using some sort of sorcery, she gains access to the room and proceeds to plant an explosive device.
The mice, having witnessed the woman's movements, alert The Voltron Force. While they are warned in time to pitch the device, Twila escapes and Hunk follows her. After tracking her down, Hunk learns that a condition of her release was to betray them and also that her brother has been changed into a Robeast. This Robeast arrives as they are talking so Hunk must join his team. Twila watches the ensuing battle and is devastated when her brother is destroyed. Lance gets a smooch from Allura at the end.