Producer James Goss said: "I love that Ace and Mr Colchester work so well as a pairing. Their third outing sees them on opposite sides of a moral dilemma.

"Mr Colchester is working for 'A Sinister Mining Company' and Ace is doing all she can to bring them down. Obviously, they're at loggerheads from the get-go, and the story is about the game of cat and mouse they play with each other.

"The notion came from designer Sean Longmore, who suggested I watch How To Blow Up A Pipeline – which is, again, about activists and authorities squaring off against each other and also lots of explosions. This story features both Ms McShane, patient head of a powerful charity trying to do the right thing, and also Ace, her inner teenager who solves every problem by blowing it up.

"All the scenes with Sophie and Paul are delights as they enjoy sparking off each other so much."

Sophie Aldred said: “It’s been great to have another look at what Ace is up to with her charity, relating to a subject very dear to my own heart – environmental pollution and the future of the planet. Ace has always been righteous, and it’s been wonderful to play her doing quite nefarious deeds, but for a good cause. The Nitro-9 is out in force!"

Paul Clayton added: “Sophie and I have made two adventures together before, and we have great fun in the studio. With this one, it’s really nice to change the dynamic between Ace and Mr Colchester. He's quite frank, no-nonsense, and in this adventure we have him being more passionate – we’ve been able to do a bit of shouting acting!”

Shaheen Khan, Anant Varman, Tom Hanson, Paul Clayton, Sophie Aldred