S1·E5 Mentor

The team intervenes on a planet when one group of the locals, the Mystari, use high-tech weapons to attack another faction – they meet up with Shepherd, a former Stargate team member who trained Gus. Shepherd claims the faction his men attacked are bandits but his followers worship him. Gus overlooks his apparent abuse until Stacey brings him around. Knowing Gus will act against him, Shepherd summons the Tlak'khan but when he finds out they plan to kill the team he and the locals side with Gus. Shepherd tells the Mystari to find their own way and then takes off on his own.