Steed and Mrs Peel are investigating the theft of several top secret documents. The evidence points to an invisible man committing these acts. In reality it is the work of Major Vazin and his wife Elena, two top spies. They are trying to convince everyone that they have possession of a secret invisibility formula, which is untrue.
Elena captures Mrs Peel and makes her believe that they are using the formula to steal documents. She tries to let her escape thinking that she will tell everyone about the formula. However, MRs Peel sees through the phoney trick and return to the Embassy to deal with the villianess.
Elena tries to draw a gun, but Mrs Peel is to quick and engages in a fight with Elena. Mrs Peel has superior fighting skills to Elena and throws her across the room and onto a sofa. Mrs Peel finally sends Elena across the floor where she crashes into a filing cabinet and is knocked senseless. Before she can recover one of the drawers come out and hits her on the head, knocking her out.
Elena is deceptive and created a scheme to make everyone believe they had a formula for invisibility. When her plan failed Elena attacked Mrs Peel. During the fight she used a very vicious fighting style, attempting to claw the eyes, grab breasts and kick towards her groin.