“Beast of Burden” is episode seven of season five of Stargate SG-1.
Chaka, a Unas that Daniel met, and befriended, on the Goa’uld’s original homeworld in “The First Ones” (the Unas being the original Goa’uld hosts), is captured by slave traders – whilst Daniel is watching using a remote camera. The people who abducted him look to not be very advanced technologically themselves, but have Goa’uld technology. Daniel wants to find out what Chaka’s abductors want, and hopefully rescue him.
O’Neill and Daniel make contact, posing as traders. The people who captured Chaka have got many other Unas working for them. It turns out that the Unas had previously enslaved them whilst working for a Goa’uld overlord. So this is about revenge, enslaving those who originally enslaved them. Even though it was actually a Goa’uld that did the enslaving.