At the giant IPAC plant a few miles outside London an intruder is disturbed by Thorson, a security guard. Thorson is coshed on the back of the head and killed. The intruder escapes with a copy of the secret Zambia order.
An unnamed superior assigns Steed to the case. He explains that secret information is being stolen from IPAC, enabling foreign competitors to undercut their prices and to undermine any technological advances IPAC have prepared. The man suggests that Steed work undercover as an Efficiency Expert, and that he take Mrs Peel along as his secretary.
At the plant, Steed liases with William Jameson, IPACs Managing Director. He tells Steed that he has a free hand, and that he can pick up any extra detail from Ed Lakin, the Works Manager. It is unclear as to whether this is referring to Steeds task as Efficiency Expert, or his clandestine investigations. Steed and Mrs Peel move into an office in the IPACs main office block.
Two days later, Steed is involved in angry scenes with Ed Lakin and Bill Kerry, head of the drawing office. They think he is a jobsworth, but in the estimating department an unnamed worker begins to wonder exactly what Steeds position at the factory is.
In the meantime, Mrs Peel is putting the feelers out. Gossiping with Myra, another secretary, she discovers that Ralston, of Estimates, could be guilty of stealing a phial of top secret chemicals. She tells Steed and he engineers Ralstons absence from the office so that Mrs Peel can search his desk. He returns early and catches her in the act. She notices that his eyes are staring mad and attempts to rush past him. He blocks her path, so she knocks him to the ground. She tells him that she was leaving a note from Steed on his desk and he apologises for his behaviour.
Mrs Peel tells Steed that she thinks Ralston is a drug addict, and that the phial his secretary discovered more than likely contained drugs. The next day he pays a visit to Steed (incidentally, this is one of the points at which Steed is referred to as Drake). Steed winds him up by suggesting that they get a new, more efficient, computing system in. A mysterious man decides to investigate the pair, and has Rolfe rifle through their rooms. Rolfe finds nothing to undermine Steeds cover, but he is caught in the act by the dapper agent. They tussle and Steed knocks him out.
Steed decides that its time to force the hand of their quarry by leaking the false information that IPAC have developed a technology known as U.R.I., which will reduce the production costs of man-made fibres. The rumour spreads around the office like wildfire.
In the meantime, the mysterious man realises that Rolfe has been caught and he decides that must spring the U.R.I. trap, just in case Steed is a genuine Efficiency Expert. Later that night he creeps into the office wearing a gas mask and carrying a gas bomb. He gasses the guards and opens the safe where the top secret formula is supposed to be hidden. Inside he finds a single sheet of paper, on which is written, U.R.1. You are one all right. Look behind you He spins around to find Steed covering him with a gun. He reacts by throwing another gas bomb. Steed makes a flying leap and, catching the bomb, prevents it from igniting. Mrs Peel steps from behind a curtain and pulls a gun on Ralston. He throws his bag at her, knocking the gun to the ground. This proves fruitless as Mrs Peel tackles him to the ground and unmasks him to reveal Kerry.
Comment the denouement of this story is somewhat compromised by the unfortunate fact that all the men in the story, with the exception of Steed, look exactly the same thus eliminating any suspense when the villain is finally unleashed. This story proves, much as The £50,000 Breakfast did on telly, that the post-Blackman Avengers could not work in mundane settings such as the factory one utilised here.