Blue Boxes is the latest Doctor Who Short Trip, set in Season Seven, with the Third Doctor still adjusting to his Earthbound exile.

With UNIT’s telephones under attack, and some mysterious deaths, the Doctor and Liz Shaw dive into the world of ‘Phreaking’. Like early hackers, the ingenious phreakers used homemade generators to replicate the internal tones a telephone system uses to communicate. This allowed them to make free calls, with their multi-frequency generators being the eponymous “Blue Boxes”.

Party Line

Writer Erin Horáková, in an impressive Big Finish debut, beautifully evokes the clandestine world of the phreakers. There is also a real sense of the time, with deaths in phone boxes. As well as considering the Doctor’s new predicament, she also captures the spirit of the formidable Liz Shaw; we repeatedly found ourselves smiling at Liz’s interactions with the Doctor and her commentary on his situation.

We loved the notion of the pair joining a “party line” meeting of teenagers, the Zoom call of its day, each with their amusing pseudonyms.

By drawing on the story of “Crunch”, the technical details did not overwhelm; a real-life American phreaker, he famously discovered that a tone to trigger trunk calls could be perfectly replicated by a free cereal box toy. There was also a pleasing element of restraint, as the whole affair concludes without recourse to the obvious sonic screwdriver!

Whistle through

On narration duties, Mark Reynolds gives another assured performance and we easily found ourselves drawn into a story that whistled through its thirty-three minute duration in no time; he has been a great addition to the roster of narrators this year.

As another year of Short Trips draws to a close, we look forward to a rare appearance by the Tenth Doctor next month, taking on the Time Agency in The Shattered Hourglass.

Doctor Who – Short Trips: Blue Boxes is available on download from Big Finish.