Forsaken

SG-1 finds a wrecked spacecraft whose crew claims to have been fighting off aggressive aliens ever since they crashed. It later turns out that the crew are in fact prisoners of the Serrakin ship Ceberus. The Serrakin are an advanced race who once helped free the human Hebridans, descendends from the Celts, from the Goa'uld millennia ago. Since then, the two peoples have lived together in a largely harmonious society on the planet Hebridan.