Criss-Cross (audio story)

Criss-Cross
Doctor:	Sixth Doctor
Companion(s):	Constance
Main enemy:	Waveform, Chuadri, Flint
Main setting:	Bletchley Park, 1944
Key crew
Publisher:	Big Finish Productions
Writer:	Matt Fitton
Director:	Ken Bentley
Producer:	David Richardson
Music:	Steve Foxon
Sound:	Steve Foxon
Cover by:	Tom Webster
Release details
Number of parts:	4
Release number:	204
Release date:	15 September 2015
Format:	2 CDs Download
Production code:	BFPDWCD204
ISBN:	ISBN 978-1-78178-547-8 (physical); ISBN 978-1-78178-548-5 (digital)
Official trailer
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Music suite
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Main Range
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Criss-Cross was the two hundred and fourth story in Big Finish's monthly range. It was written by Matt Fitton and featured Colin Baker as the Sixth Doctor and formally introduced Miranda Raison as the new companion Constance Clarke.

Constance had previously appeared in The Sixth Doctor: The Last Adventure due to its earlier than previously scheduled release. This was meant to be Constance's audio debut.

Publisher's summary

Bletchley Park. Britain's most secret weapon in the Second World War.

Inside draughty huts, the earliest computers clatter day and night, decoding enemy transmissions and revealing intelligence crucial to the country's defence. Leading WREN Mrs Constance Clarke directs her charges to provide vital assistance to the boffins stationed in the Manor House. But a recent arrival among the code-breakers, the mysterious Dr Smith, has attracted the attention of MI5's spycatchers...

Over in mainland Europe, Nazi agents are briefed, covert operations planned, and a German submarine embarks on a very secret mission.

As encrypted radio waves criss-cross the planet, unearthly forces stir. And when certain cyphers are cracked, something will emerge to threaten all humanity, regardless of allegiance...

Until now...

Plot

Part one

Bletchley Park, 1944. Leading Wren Constance Clarke has been assigning her subordinates to their positions, but she finds fellow Wren Sylvia Wimpole crying due to having been put on three successive shifts by the code-breaker she has been assisting - a new arrival calling himself Doctor John Smith. Confronting the Doctor at his office in Hut 12A, Constance agrees to assist him with a secret project he has been working on: the phrase “golden eggs” keeps appearing in messages surrounding one Agent Spark.

After some more work, the Doctor and Sylvia have made some progress in their investigation into Agent Spark. The Doctor tells her that he hadn’t intended to stay for so long, but, as he bitterly notes, his ship is completely dead. Suddenly, they come across the plans for Agent Spark and Henrik van Nyman, known as Agent Tulip, to be dropped into Cambridgeshire that night. Sylvia asks if the Doctor will send troops to intercept them, but he instead decides that the two of them will drive to Cambridgeshire personally. The Doctor is able to convince Constance to provide him with a vehicle, but Major Harris has been investigating the Doctor and has concluded that he is a spy. To get away from him and his troops, the Doctor throws himself out of his office window and sprints to the car that Constance and Sylvia are waiting in, barely able to drive off in time.

They arrive at the location mentioned in the messages and find a very makeshift camp nearby some factory buildings - alongside a set of footprints. The Doctor tells Sylvia to investigate the camp while he and Constance follow the footprints. Sylvia finds a knapsack containing ciphers and, at the bottom, a golden egg - but soon finds herself at the end of the barrel of van Nyman’s gun. Suddenly, an unknown voice speaks numbers in their minds, killing van Nyman and nearly killing Sylvia. The Doctor and Constance hear Sylvia’s scream, but have more pressing matters to deal with: a bomb planted at the factory buildings. The Doctor cuts the red wire on the main module, but quickly realises that this was the wrong choice!

Part two

“Agent Spark”, real name Robbie Flint, actually works for the British, under the codename Agent Criss-Cross, and set up the fake bomb to continue the ruse. He meets up with Harris and tells him about van Nyman’s death, as well as the presence of “some bloke” and the two Wrens at the factory, before showing Harris the contents of his knapsack. Flint explains that the Germans keep finding golden eggs off the Brittany coast, and that he stole this one from his commanding officer. The egg opens and a synthesised voice begins speaking numbers, but before they can investigate, a captain arrives to inform them that the man with the Wrens at the factory was indeed the Doctor, and Harris gives the order to move out.

To the Doctor and Constance’s surprise, nothing explodes, and the Doctor realises that the “bomb” is actually a fake. He and Constance go to where Sylvia screamed, and find van Nyman dead - killed by soundwaves. The two of them drag Sylvia’s unconscious body to the TARDIS, but before they can make it inside, they are surrounded by soldiers, including Harris. Harris, Flint, Constance and the Doctor enter the TARDIS, and are so stunned by its true nature that Harris gives up on arresting the Doctor. The Doctor deduces that Flint is indeed Agent Spark, and Flint gives him the egg to analyse. He explains that the TARDIS has been disabled since it landed on Earth, with its signals scrambled by some kind of code, and he came to Bletchley to work out how to fix it. The code he had been tracking kept appearing in messages containing the phrase “golden eggs” and mentioning Agent Spark. The Doctor posits that the eggs are in fact reconnaissance beacons, from an extraterrestrial ship lying at the bottom of the sea off the coast of Brittany, and he reveals to the three of them that he is, in fact, an alien. Harris leaves to fetch his men so that the Doctor can fly them to the craft in the TARDIS, but Flint pulls a gun on the Doctor - he is unconvinced by the Doctor’s explanation. Ignoring him, the Doctor dematerialises the TARDIS before Harris’s very eyes.

Dr Volke Schwartzmann, a Nazi official who Flint was “working” with, is descending to the bottom of the ocean in a U-boat, captained by Unger. Suddenly, the submarine takes on a large amount of weight - the TARDIS, as the Doctor and his companions are quick to discover when they suddenly have Unger’s gun pointed at them. Schwartzmann arrives soon after, and Flint tells him that the Doctor and Constance are his prisoners. The Doctor realises that in bringing the beacons to their source, Schwartzmann has accidentally unleashed a living creature, the Waveform, who burrows its way into the Doctor’s mind…

Part three

The Doctor deduces that the Waveform is sentient electromagnetism, and convinces it to try another way of becoming corporeal. He pleads with the Waveform not to use its physical interface, the Chuadri, not to hurt the humans, and the Germans not to fire on it, but he is unsuccessful and the U-boat crew are killed. Constance and Flint run away, and the Waveform tells the Doctor and Schwartzmann that it is trying to flee a war by escaping to a longer wavelength, and that this has brought it into their world. It is unable to leave Earth due to the electromagnetic signals crossing over the Earth, and it has sent out thousands of distress calls - one of which disabled the TARDIS. The Doctor decides that once his TARDIS is operable, he will take the Waveform away from Earth - but suddenly, the U-boat strikes the seafloor and begins flooding. Once the Doctor, Constance, Flint and Schwartzmann get back to the TARDIS, the Doctor is able to fly it back to his office in Bletchley, with the assistance of the Waveform.

Harris and Sylvia are in the Doctor’s office when they arrive. Constance is the first to get out, and puts them straight back to work before heading off with Harris. Flint collects up the reconnaissance beacons while the Doctor, Schwartzmann and the Waveform leave the TARDIS. Harris and Constance re-enter the office soon after and the Doctor tells Harris to ensure that nobody is to leave their rooms.

The Doctor joins Constance at the room where the Wrens are working on helping the Waveform. Suddenly, however, they realise that it has vanished, and the Doctor worries that it may have been subsumed by the radio transmissions present in the atmosphere. He attempts to contact it, but what come through instead are the Chuadri! The Doctor tells the Wrens to carry on working but he and Constance run back to his office. The Waveform has tricked the Doctor, as it wants to drain power from both Earth’s electromagnetic waves, and its people, in order to win the war it has been fighting. The Doctor realises that the Waveform would only be able to make any real progress if it had access to ciphers from both sides - and the one giving them to it was Flint all along, who is now pointing a gun straight at the Doctor…

Part four

Constance uses a signal jammer she had constructed to temporarily disable the Waveform and allow the Doctor, Schwartzmann and herself to escape from Flint. They run to Harris and tell him to order his men to stop firing on the Chuadri. Midnight strikes, and Constance realises that since the Germans have changed the codes, the Waveform will be unable to act for a few minutes. The Doctor hurries over to Sylvia’s hut and Harris orders his men to cover the exits, while Constance and Schwartzmann follow after the Doctor. On arriving at Sylvia’s hut, the Doctor tells Sylvia to create a cipher so complicated that the Waveform will have no way of decrypting it, and Schwartzmann volunteers to help. Harris arrives soon after and he goes with the Doctor to Hut 12A.

The two of them find Flint and the Waveform unable to decrypt a message from Nazi High Command. The Doctor tries and fails to convince Flint to stop helping the Waveform, and Flint forces the Doctor to take them to the Colossus machine and decode all the messages. However, the Doctor has already told Sylvia to turn on the transmitter in the radio hut and broadcast a message, and has instructed Constance to build a device inside the TARDIS to boost the signal all around Bletchley. The very low frequency of the message means that the Waveform is now unable to receive or transmit anything. The TARDIS has been able to boost the VLF signal, blocking the Waveform slightly and thus allowing the TARDIS to boost the VLF signal even more, and so on. All of this means that the Waveform is now completely trapped, unable to escape without deciphering Sylvia’s message - but the cipher she crafted, using the Waveform’s own name, is completely impossible to crack. The Waveform retreats inside one of the beacons, taking Flint with it.

After saying goodbye to Sylvia, the Doctor is about to leave in his TARDIS, when Constance catches up with him and practically forces him to let her come with him. With a new companion in tow, the Doctor sets off.

Cast

• The Doctor - Colin Baker
• Constance Clarke - Miranda Raison
• Robbie Flint / Cyril - Paul Thornley
• Major Harris / German Lieutenant - Alistair Petrie
• Dr Schwartzmann / Rider - Hugh Fraser
• Sylvia Wimpole / Waveform / Effy - Charlotte Salt
• Captain Unger / Dutch / British Captain / Chuadri - Robbie Stevens

Crew

• Cover Art - Tom Webster
• Director - Ken Bentley
• Executive Producers - Nicholas Briggs and Jason Haigh-Ellery
• Music & Sound Designer - Steve Foxon
• Producer - David Richardson
• Script Editor - Alan Barnes
• Writer - Matt Fitton

Worldbuilding

• The Doctor uses his common alias "Dr John Smith" while working in Hut 12A at Bletchley Park.
• Sylvia Wimpole was a mathematical prodigy at the University of Cambridge.
• Robbie Flint claims that he was the best safe cracker in Bermondsey in the 1930s.
• Flint speaks both German and French.
• Constance grew up in Nyasaland. She returned to the United Kingdom after her father died of tuberculosis.
• Constance began working at Bletchley in 1940.
• Constance's husband Lieutenant Commander Henry Clarke is a member of the Naval Intelligence Service. He was posted to special duties in November 1943.
• The Doctor has signed the Official Secrets Act several times.
• Constance received a first in modern languages at Somerville College, University of Oxford.
• Constance was on duty in spring 1941 the night that Alan Turing cracked the code.
• The Doctor compares the ingenuity of Bletchley Park to Logopolis.
• The Doctor mockingly refers to Flint as "Lord Haw Haw" and the Chuadri as "Casper the Friendly Ghost".

Notes

• This story was recorded at The Moat Studios.
• On the cover, The Doctor is shown wearing a new costume comprising of a Bletchley tweed, a dark waistcoat, blue shirt and a bow-tie. He would wear it again on the cover of Quicksilver.
• Subscriptions that included this story also included the audio short story The Warren Legacy.
• According to the extras, the script to The End of the Line, the first story in which Constance appeared, was written prior to Criss-Cross even though this story was intended to be released before it.

Continuity

• The Doctor again expresses a fondness for fishing. (TV: The Androids of Tara, The Two Doctors)
• Major Harris thinks that Winston Churchill would love to get hold of a machine like the TARDIS. (TV: Victory of the Daleks , AUDIO: Their Finest Hour et al)
• The Doctor refers to Alan Turing. During his eighth incarnation, the Doctor would later receive help from Turing in cracking an alien code in 1944. (PROSE: The Turing Test)
• The Doctor claims that Bletchley Park almost puts Logopolis to shame. (TV: Logopolis)
• Kinvar detected the Doctor's presence while he was at Bletchley Park and waited several months for him to return. (AUDIO: Quicksilver)

External links

• Official Criss-Cross page at bigfinish.com