Two prisoners meet in a prison cell. Zara is searching for the segments of the Key to Time; she was only born yesterday but already she's killed hundreds of people. Ace is more ambitious: she was going to kill everyone on the planet.
What have they got against the people of Erratoon? They go peaceably about their simple assignments, beneath their artificial sky. They share their meals and leisure time and they never ask questions. Are they even real?
Ace and Zara will only survive if they can trust each other. Or perhaps if they sell each other out... If not their awful punishment is to become just like everyone else.
to be added
- Zara refers to the Grace, the Tracers, the Key to Time, the White Guardian and the Black Guardian.
- Ace mentions Florana, the Eye of Orion and being quite an expert on making explosions.
- Harmonious 14 Zink uses a Time Ring.
- Zink was married to 1V Magda.
- Unlike most other Big Finish Productions audios, this story is set during the Virgin New Adventures era. Bernice Summerfield is mentioned but not named. One other Companion Chronicle, Bernice Summerfield and the Criminal Code, is set during that era, although Ace is absent from that story.
- This story is narratively linked to the audio story The Judgement of Isskar, which was likewise released in January 2009.
- This audio drama was recorded on 16 June 2008.
- Ace tells Zara that she once met a "bloke made of liquorice." (TV: The Happiness Patrol)
- Zara is the twin sister of the Fifth Doctor's former companion Amy (later Abby). The Doctor previously encountered Zara on Mars in the distant past (AUDIO: The Judgement of Isskar) and on Chaos at the end of recorded time (AUDIO: The Chaos Pool). Both of these events have yet to take place in her personal timeline.
- Ace uses logic to confuse the Robot Constables. (TV: The Curse of Fenric)
- Ace has had her memories removed once before. (PROSE: Timewyrm: Genesys)
- Ace remembers travelling with the Doctor and a woman wearing earrings who "knew a lot about dead things." (PROSE: Love and War)
- Ace mentions visiting the Trib Museum. (AUDIO: The Lost Museum)
- Ace vaguely recalls her mother bringing someone to a wedding, (PROSE: Happy Endings) and that she had previously met them when they was the same age as her. (PROSE: Nightshade)
- Ace mentions having Christmas dinner in Cheldon Bonniface in 1992. (PROSE: Timewyrm: Revelation)
- Zara refers to the fact that the Fourth Doctor and Romana went on the run after assembling the Key to Time. (TV: The Armageddon Factor)