Production Code: BFPAVENGE005


Steed is instructed by One-Ten to infiltrate an organisation which specialises in smuggling diamonds from London to New York. He is to take up residence in a bungalow near Heathrow Airport, which used to belong to an air steward called Frank Harcourt, an apparent suicide who is believed to have been connected to the smugglers. Steed will work under cover using the identity of John Ryan, another air steward, who was recently arrested in Australia on suspicion of smuggling. It is hoped that with this suitably crooked back-story, he will be invited to join the illicit operation.

Starting his new job, Steed meets Fiona Charles, an attractive but humourless nurse employed by Dr Collard, the tediously dull medical adviser to Globe Airlines; the enthusiastic Captain Sharp, the pilot with whom 'John Ryan' will be flying to New York; and Stella Creighton, a stewardess who seems rather on edge about something. Steed would like to find out more about Stella, but whenever he tries to get close to her, Captain Sharp has an uncanny knack for getting in the way.

Following a wild party, Steed very much the worse for wear - is awoken by a telephone call. A mysterious voice advises him to read the morning paper. It carries a story about a young woman who was killed in a hit-and-run accident the previous night. Told by the caller to check his car, Steed is horrified to find that it is dented and covered in dried blood...

Click here to read about the original television episode

The Avengers - The Lost Episodes:
Volume 5, Episode 4
Recording Dates:
6, 7, 19, 20 May 2015
Recorded at: Moat Studios
and Soundhouse Studios
Duration: 48 minutes 14 seconds


Released as a part of
The Avengers - The Lost Episodes,Volume 5
Release Date:
21 Jan 2016
Physical Release: Audio CD
Download Release:
MP3 / M4B Formats
Dr David Keel
John Steed
Carol Wilson
Captain Sharp
Fiona Charles
Doctor Collard
US Customs
Stella Creighton
US Tannoy
Anthony Howell
Julian Wadham
Lucy Briggs-Owen
Dan Starkey
Dan Starkey
Dan Starkey
Dan Starkey
Helen Goldwyn
Helen Goldwyn
Justin Avoth
Justin Avoth
Justin Avoth
Alice Haig
Anjella Mackintosh
Anjella Mackintosh

At the present time, no original soundtrack has been released by Big Finish.


Production Notes Booklet (with CD only) Interviews with actors Julian Wadham, Dan Starkey and writer John Dorney


Purchase from Big Finish


Writer Max Marquis
Adapted for audio by -
John Dorney
Recording and Music
Toby Hrycek-Robinson at Moat Studios
(some material recorded at Soundhouse Studios)
Sound Design and CD Mastering
Richard Fox and Lauren Yason
Series Theme -
Johnny Dankworth, rearranged by Toby Hrycek-Robinson
CD Extras -
Jamie Griffiths
CD Interviews -
David Richardson
BFP Administration -
Miles Haigh-Ellery, Cheryl Bly and Alison Taylor
Producers' Assistants - Ian Atkins, Sue Cowley, Emily de Fraine, Hannah Peel,
Joseph Smith, Paul Spragg and Frances Welsh
Cover Illustration -
Anthony Lamb
Booklet Design -
Mark Plastow
Booklet Notes -
Richard McGinlay
Web Services -
Hughes Media
Marketing Consultant -
Kris Griffin
David Richardson
Executive Producers -
Nicholas Briggs and Jason Haigh-Ellery
Ken Bentley

Thanks to Massimo Moretti, Brian Clemens, Sam Clemens, Marcus Hearn, Richard McGinlay,
Jaz Wiseman, Alan Hayes and Toby Hrycek-Robinson


A Big Finish Production


  • Production Brief... This audio play is based on the television episode Diamond Cut Diamond, which was originally broadcast on Saturday 18th February 1961 at 10.00pm in the ABC Midlands, ABC North and Anglia ITV regions. It was the first Avengers episode to be transmitted by Anglia Television, which picked up the series earlier than any other non-ABC ITV region.

  • The television version of Diamond Cut Diamond does not survive today. Nor does the original script written by Max Marquis. However, storyline synopses exist, along with a single production photograph (see Brought to Audiobook...).

  • The audio adaptation of this episode was recorded at Moat Studios (with some material recorded at Soundhouse Studios) on 6th, 7th, 19th and 20th May 2015. Four episodes were recorded during these sessions: Nightmare, Girl on the Trapeze, Crescent Moon and Diamond Cut Diamond.

  • Brought to Audiobook... John Dorney, who developed the audio script from a storyline by Max Marquis, had a bit more to go on compared with the other two 'script-less' episodes in Volume 5, but not by much. The bulk of his creative extrapolation goes into the first couple of acts of the audio play, where he adds previously unimagined character development for Harcourt and Stella, and places plenty of obstacles in the way of Steed's investigation before the agent finally receives that fateful phone call from his would-be blackmailer.

  • In previously published synopses, the character of Harcourt is already dead as the story begins, but in the audio adaptation he has a few lines of dialogue during the opening teaser. This arguably deprives the tale of some of its mystery, by revealing that Harcourt's death is not suicide. Then again, perhaps this wasn't such an enigma in the first place - the TV Times synopsis for Diamond Cut Diamond makes it plain that Steed "joins an airline to find a murderer".

  • It was unclear until now whether the real John Ryan was an Australian or just happened to be in Australia when he was arrested for smuggling. Writer John Dorney has decided to make him Australian, and so Julian Wadham adopts a suitable accent whenever Steed poses as the corrupt air steward. This does draw attention to the plot's similarity to Square Root of Evil, in which Steed infiltrated another gang of criminals by masquerading as a known offender with a non-English accent. However, there's no denying that it's a useful form of disguise in an audio production.

  • Dorney has conceived a very different role for the character of Stella Creighton than had hitherto been envisaged. This character is billed in cast lists but not directly referenced in the episode summary that appears in The Complete Avengers. In that synopsis, Steed is manoeuvred into smuggling a package to "someone in New York", and the authors of this website and the book Two Against the Underworld had surmised that Stella was that someone. This reasoning is based upon a process of elimination and also the fact that Stella is billed last in order of appearance in TV Times (after Keel, who had no documented role in the episode prior to Steed being framed and turning to the doctor for help). However, Dorney reaches an entirely different, but equally valid, conclusion: that Stella is the victim of the hit-and-run incident in which Steed is implicated. The writer also adds previously undocumented scenes featuring Keel at earlier points in the narrative, thus allowing Stella to play her ill-fated role without contradicting the TV Times cast list.

  • Conversely, Captain Sharp is mentioned in the Complete Avengers synopsis, but not in contemporary cast lists (possibly because the part was not cast until a relatively late stage). The character is not really described in the synopsis, and one can only assume that his function was to divert attention away from the real villain. Therefore, Dorney and actor Dan Starkey portray the captain as a suitably suspicious individual.

  • In addition to synopses, a single production still is known to survive from the television episode. It was reproduced in Patrick Macnee's 1997 book, The Avengers and Me (co-written with Dave Rogers), and shows a concerned-looking Steed on the telephone while Fiona Charles (played on screen by Sandra Dorne) weeps onto his shoulder. This helps to inform a plot development in the third and final act of the audio production.

  • One apparent shortcoming of Marquis' storyline is that the villains' scheme seems rather more likely to attract unwanted attention than to have the desired effect of covering the gang's tracks, leaving behind a trail of unfortunate victims. Dorney addresses this criticism in his script by having Keel point it out.

  • Steed's substitution of fake diamonds for the real ones is inspired not by the synopsis for Diamond Cut Diamond but for that of a later Series 1 episode, Please Don't Feed the Animals. In the latter storyline, Steed is apparently blackmailed into handing over some top-secret ciphers, but he switches them for false information. This plot development did not make it into the final script of Please Don't Feed the Animals possibly because it had already been done in Diamond Cut Diamond.

  • Trivia... The use and abuse of barbiturates is a recurring theme during Series 1 of The Avengers. Barbiturates act as central nervous system depressants with a wide variety of effects, ranging from mild sedation to total anaesthesia. In Diamond Cut Diamond, Steed is doped into insensibility by a massive dose of the drugs. Elsewhere in this box set, in Girl on the Trapeze, Katrina Sandor is killed by a barbiturate overdose. Earlier still, in Brought to Book, Keel threatens Spicer with a supposedly lethal injection, but in fact his syringe contains "a harmless barbiturate". Nowadays, barbiturates are known to be far from harmless. They can be addictive, and have largely been replaced by benzodiazepines in routine medical practice, primarily because benzodiazepines are less dangerous in overdose.

  • Steed is one man with two guvnors in this box set! Whereas he reports to '5' in Crescent Moon, in Diamond Cut Diamond he is briefed by the more familiar One-Ten. The television version of Diamond Cut Diamond marked the earliest known appearance of One-Ten, though in terms of the audio productions this is the sixth time that actor Dan Starkey has taken on the role, so he's an old hand at it by now. He also provides yet another distinctly different voice in this episode, that of the ebullient Captain Sharp. What with this on top of writing Nightmare, playing Vasco and Fernandez in Crescent Moon, not to mention portraying umpteen Sontarans in Doctor Who on screen and audio, is there no end to this man's talents?

  • The CD booklet accompanying this release carried a dedication to actor Patrick Macnee, who died on 25th June 2015. This sentiment was reinforced on the Diamond Cut Diamond disc with a bonus interview feature in which writer John Dorney and actors Dan Starkey (One-Ten) and Julian Wadham (Steed) paid tribute to Macnee. This was recorded during a studio session for the Steed and Mrs Peel audio series.

  • And Finally... A Tannoy announcement during the closing act of the audio play advises passengers for MJN Air's flight to Paris to proceed to gate number three. This is a sly reference to the BBC Radio 4 situation comedy Cabin Pressure, written and created by John Finnemore, which details the exploits of the oddball crew of the single aeroplane operated by two-bit airline MJN Air. Company owner Carolyn Knapp-Shappey (played by Stephanie Cole) acquired the plane as part of her divorce settlement with her husband Gordon Shappey (Timothy West). The company name stands for "My Jet Now"!

Plotline by Richard McGinlay Declassified by Richard McGinlay
Big Finish Productions Reproduced with permission

With thanks to David Richardson, John Dorney, Mark Plastow, Kenny Smith
and Big Finish Productions for their kind assistance


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