by Margery Allingham ; screenplay by Alan Plater ; directed by Martyn Friend ; a BBC Television production ; in association with Consolidated Productions ; produced by Ken Riddington
producer/directors, Serena Davies, Tom Hewitson, Ross Kirby, Laura Mulholland, Simon Winchcombe ; executive producer, Rob Liddell ; BBC Studios, the Science Unit
producer/directors, Simon Bowyer, Kieran Carruthers, Tina Curley, Craig Ellis, Anton Inwood, Dane McDonald, Alex Reynolds, Emma Westwood ; producer, Emma Wightwick ; CurveMedia