“Memento Mori” is episode eight of season ten of Stargate SG-1.
This episode starts with Vala working in a diner for some reason. Two men try to rob the place and she, rather efficiently, incapacitates them.
The episode then goes back three weeks (a habit I’m not fond of). Daniel was taking Vala out for a meal (not a date as he insists repeatedly) when she is abducted by the Trust under the auspices of the Goa’uld Athena, who apparently has history with Vala’s former Goa’uld.
Athena wants some information from her and has her wired up to a machine to help get it. When SGC try to rescue Vala, the machine is hit by a zat bolt and she gets the effects transmitted into her head, damaging her memories. Which is why she is working in a diner – she can’t remember who she is.
SG-1 have to try and find her when she isn’t wanting to be found, as she doesn’t know who to trust.