ATV for ITV, 10 September 1977 to 3 May 80 (4 series)
This 45-minute espionage game show began with "Inspector Clouseau" cartoon-style titles, as an agent in a mac passed eyes in the dark, lit a fuse with his cigar, and watched the fuse fizzle across the screen (behind "Masterspy" William Franklyn, well-known in those days as the voice of the Schweppes ads) until a bomb exploded. Jenny Lee-Wright played "Miss Moneypacker".
The setting and plot for each show varied, but the concept was always that of three agents going on a mission, and being given cover stories which they had to learn and rehearse in order to accomplish tasks, often involving actors (including David Jason, fact fans) who were playing a variety of sinister or enigmatic characters. Beforehand, contestants were sent a series of letters and packets from "The Department of Hazardous Projects", usually from the desk of "R. J. Bingham-Sterndale" (really the producer's secretary, Cherry Taylor).
For example, one contestant was briefed as a philatelist, and sent a sheaf of material on stamps and postmarks which had to be memorised. During the show the contestants were interrogated but not kept informed of the scores (well, nobody tells an agent in real life how well he's doing as he goes along). Contestants dropped marks heavily if they "blew their cover".
Round One involved giving instructions to the agents, interviewed one at a time, often involving a logic game: Three envelopes, one marked with a cross, are placed on the table. Franklyn: "Everything I tell you from now on is a lie. One of these envelopes is not empty. The envelope in the middle is not the empty envelope. The envelope with your instructions is not at the far end from the envelope without the cross on it." He hands over a paperknife, saying, "This is not a paperknife!" and the fuddled agent has to work out which one to open.
Then an observation exercise: "Look at this picture of the Hotel Salome in Bratislava" which would be whisked away five seconds later. The agent was then asked to describe everything that they'd observed in the picture, and points (though this wasn't specified) were given for each fact correctly remembered. There might also be a film, with questions afterwards.
Next came a practical test, such as handcuffing all three agents to a wooden "maze" wall and waiting to see who could first slide their handcuffs up, down, along and round, and free themselves from the wall in order to reach a key on a nearby table. (This was in preparation for a "free the captured agent from being handcuffed to the towel rail in the bathroom" in the final round.)
Another round involved a grilling on the material learned for the agent's "cover story" - a philatelist would be asked about various terms in the hobby, a travel agent about ferries between England and Sweden, perhaps, all from the briefing material that had been sent out a couple of weeks earlier for study.
We also met Agent X, a heavily-disguised celebrity (such as Clement Freud or Bobby Moore) whom the contestants were allowed to ask questions that led to Yes/No answers only (the more Yes answers your questions produced, the more points you scored). Once you guessed their name, you wrote it down. The lowest-scoring agent was eliminated first, leaving the other two to battle it out head-to-head.
The least successful agent would be dropped, and the last round was a sort of improvised play, where professional actors had learned their roles, and the two remaining agents had to try to cajole, argue or trick their way into getting what they wanted. Some of the tasks were based on the skills they had learned throughout the show. When necessary, William Franklyn would broadcast questions on the agents' radios, or ask them what they planned to do next, in order to provoke them into getting on with it if they were floundering. Agents didn't always know what their true objective was, but had to react to events, and show ingenuity. If a contestant did something wrong, the other would take over the mission. Each agent got a prize for taking part, increasing in value if they were more successful.
The winner was allowed to choose one item from the set (as happened in Trivial Pursuit). Prizes came in the form of 70s gadgetry such as a black and white portable TV, radio cassette or pocket calculator.
The show was devised and produced by Ronnie Taylor, and came to a premature end when he sadly died.