Medusa and the Inhumans - S1.E5

Herbie is helping Ben exercise using Reed's testing room, when a mysterious lady enters their headquarters and is captured by the automatic defense systems. She introduces herself as Queen Sebel of Manopal and wishes to enlist the help of the Fantastic Four. She uses a hypnotic influence on Ben to get him to agree to the trip to Manopal along with the rest of the team. There she tells them of how the Great White Stone, a large and valuable diamond was stolen by bandits. While acknowledging a few problems with Sebel's story, such as why no one else was sent to look for the diamond, the Four agree to track it down for her by looking in the surrounding jungle. They soon come into contact with the bandits themselves, who tell the team that Sebel must be overthrown. Sue retrieves the diamond, but before she can study it, Ben and Reed, now both under Sebel's influence, insist that it must be returned to her, and leave Sue and Herbie with the bandits. She asks them what they wanted with the diamond and they tell her that she used her powers along with the diamond to enslave the people of Manopal. Sebel gets the diamond back and forces Reed, Ben and Herbie to work as slaves, and transforms Sue into diamond. Forced to work in the mines, the remaining three of the team find Miel, Sebel's sister, who was imprisoned over a thousand years ago. Reed and the rest of the team, along with Miel, are left to figure out a way of freeing both Sue and the people of Manopal from Sebel's powers.