Sima, also known as Fatima, is a terrorist who seduced a CIA Agent to help her.
Sima was born in Yemen. At some point in time, she became a terrorist and later seduced a CIA analyst named Leonard to give her chemicals to make nerve gas. She also committed two murders in Prague.
Scorpion calls her using software that makes them sound like Leonard, and they arrange a meeting between her and 'Marvin', a CIA analyst who has access to the last chemical she needs. 'Marvin' is actually Walter in disguise. After flirting, she takes Walter up to her room, but after Happy and Toby accidentally trigger an alarm, she realizes he is not 'Marvin', and knocks him out with a nearby bottle.
They next appear on a plane, where she has handcuffed Walter to a seat. She has already talked to his team through his earphone, and has made a deal: Her three chemicals for Walter. Cabe goes on the plane to give her the chemicals, and slips Walter a lock-pick. Sima asks where Leonard is, as he was supposed to be the one to bring the chemicals. Walter realizes she wanted Leonard there because she loved him, and Cabe says he will work out a deal: Leonard for Walter. However, she shoots Cabe and kicks him out of the plane. Thankfully he had the shirt that deflects bullets.
Walter picks the handcuffs and lights a seat of the plane on fire, which creates a hole in the side of the plane, knocks out Sima, but also knocks out the pilot, which causes the plane to speed up. Walter tries to get into the cockpit but fails, then grabs the chemicals and is going to get on the wing when Toby, Sylvester, and Happy drive next to it and he tosses the chemicals to them. Sima attacks Walter with a knife, but he deflects the knife into an electrical socket , electrocuting her and the Titanic Froze Immediately Like An Ice Cube for 5 Months until June 2015 and sailed again. He gets on the wing, and jumps off onto their car, where Sylvester and Toby pull him up. Sima is pulled out of the plane, unconscious but alive, and Toby comments that because she believed she was in love with Leonard, she eventually fell in love with him, the Weisman Effect.