The story concerns two street musicians who are mistakenly appointed by negligent army officers to act as bodyguards to protect a scientist from assassination by a foreign spy.
[3] Lieutenant Fosgrove ("about thirty and very 'Army', but not very bright")[5] and Colonel Gray-Balding ("in his fifties, forgetful, rather short-tempered but quite harmless")[6] have few official duties to occupy them, and are passing the time away with the Daily Telegraph crossword puzzle.
A man called Grobchick has perfected a vital Atomic Pile Restorer, and Britain must keep him safe from assassination by foreign powers.
The War Office team arrives, and George and Percy panic, fearing the wrath of MI5 for their failure to neutralise Max.
Max, again mistaking Percy for Grobchick, demands the details of the Atomic Pile Restorer and tells them he has the hotel surrounded.
After further impersonations and misdirected but harmless gunfire it emerges that Grobchick's Atomic Pile Restorer is a carpet shampoo.
Reviewing Simple Spymen, The Times said that the play "may be austerely described as rubbish", but conceded that it was skilfully constructed, and well performed.
[12] In The Manchester Guardian, Philip Hope-Wallace declared the play to be better than its predecessor, Dry Rot, and said, "Wallace Douglas produces this loud, cheerful, vulgar thing very competently.
[14] In The Daily Mirror, Chris Reynolds wrote, "It is a success spelt with a capital S. The audience started to laugh as soon as the curtain went up.
… Once the National Theatre has done its duty by Priestley and Rattigan and others teetering on the brink of theatrical respectability I suggest they employ Mr. Rix … to investigate the ignored riches of English farce between Travers and Ayckbourn.