Mission X-41 was the 24th produced episode and the 27th broadcast episode of the television series Joe 90.
Joe 90 parachutes into an enemy research station in a daring search for a secret formula.
A demonstration of the new virus X-14, shows that it is capable of breaking down the molecular structure of a building and will go on destroying everything in its path unless halted by the antibody. W.I.N. has isolated the virus but still have not perfected the antibody. The formula for this must be obtained to restore the balance of power. Joe, with the brain pattern of a top W.I.N. agent, is dropped by parachute near the enemy research station and after making plans with W.I.N. agent 84 allows himself to be captured. The General in charge of the research station is amazed at the presence of a nine year old boy and does not believe Joe when he admits to spying. While the area is being searched for Joe's non existent accomplices, agent 84 creates a diversion and in the confusion Joe manages to break into the laboratory and get the formula for the antibody. The guards realise he is free in the research station and close in on him but Joe audaciously steals one of their own aircraft and escapes, leaving the General a very confused man.