Peter Davison (The Fifth Doctor), Sylvester McCoy (The Seventh Doctor), Matthew Waterhouse (Adric), Sarah Sutton (Nyssa), Janet Fielding (Tegan), Yasmin Bannerman (Roz Forrester), Travis Oliver (Chris Cwej), Christine Kavanagh (Patience), Jeremy Hitchen (Medford/Quint/Quant/Ziyou Wanle/Ferutu), Sharon Maughan(Whitfield), Peter Caulfield (Adam/Falconstock/Sam/Concierge/Robot Voices)
A newly regenerated Fifth Doctor arrives on an occupied ice planet – where the Seventh Doctor is investigating dangerous energy experiments conducted by the Earth Empire. But events spin out of control when a refugee from the distant past arrives – Patience, the Doctor’s Wife!
Written By: Lance Parkin
Directed By: Jamie Anderson
Cold Fusion was the eleventh and final story in Big Finish Productions’ Novel Adaptations range. It was an adaptation of the novel of the same name.
Nyssa mentions Trodos and the robot uprising there in 2066. (The Trodos Tyranny)
The Seventh Doctor remembers joining his other twelve incarnations to save Gallifrey. (The Day of the Doctor)
The Seventh Doctor starts to mention an incident in which he and the Fifth Doctor encountered each other involving the Knights of Velyshaa, but the Fifth Doctor quickly stops him from talking, as he hasn’t experienced that event yet. At that time, the Fifth Doctor was travelling with Tegan and Turlough but neither was present for that event. (The Sirens of Time) The Fifth and Seventh Doctors also met shortly before dropping off their respective companions Peri Brown, Erimem, Ace and Hex in Monte Carlo in 1966. (The Veiled Leopard) they encountered each other again in the Eighth Doctor’s TARDIS The Four Doctors) and in the Factory (The Light at the End) but neither retains any memory of those meetings.
When the Fifth Doctor stops the Seventh Doctor from mentioning the Knights of Velyshaa incident, he notes that they could’ve shorted out the time differential. He then notices that his voice sounds older than it should. (Time Crash)
Both the Fifth and Seventh Doctors remember meeting Omega. (The Three Doctors) The Seventh Doctor remembers meeting Omega on four separate occasions. (Arc of Infinity; Omega)
When asked about the nature of his birth by Patience, the Fifth Doctor reveals that he was “unambiguously” loom-born. (Cat’s Cradle: Time’s Crucible)
Deviations from the original novel
No reference is made to the Scientifica using slave labour.
In the novel, the Doctor is unsure about how he was born, whereas in the audio he states that he was “unambiguously” Loom-born.
When the Fifth and Seventh Doctors are discussing past multi-Doctor events, they omit reference to how the Terrible Zodin used mind-rubbers, but mention the Knights of Velyshaa (The Sirens of Time) – which hasn’t happened for the Fifth Doctor yet – and how their recent equations will be helpful when all thirteen Doctors have to work together to save Gallifrey. (The Day of the Doctor) they also make reference to having ‘shorted out the time differential.’ (Time Crash)
Where the novel ended with Roz knocking out the Fifth Doctor and the Seventh, Roz, and Chris departing for their TARDIS via transmat, the audio adds an extra few moments where Adric, Nyssa and Tegan arrive while debating why the future Doctor doesn’t recall these events only to find the Fifth Doctor unconscious.