“Allegiance” is episode nine of season six of Stargate SG-1.
The Tok’ra are evacuating from their base after a Goa’uld attack, and when they couldn’t get through to the SGC, go through to the Alpha Site where, as well as the humans of Earth, there are numerous Jaffa.There is some initial friction between the Tok’ra and the Jaffa, as when a Tok’ra is killed, it’s usually by a Jaffa staff weapon. Matters are not helped when attempts at sabotage and murders happen.
The assassin is invisible – not the first time invisible things have been ‘seen.’
I would have thought that the Alpha Site – as it’s the last refuge for Earth, should the conflict with the Goa’uld System Lords go badly – would have been a lot bigger after several years. If it’s the place being built as a final refuge should thinks finally go to pieces, you’d think they’d spend a bit more developing it. At least make it reasonably self sustaining.