Gallifrey is in crisis: the Doctor's homeworld is being attacked by a powerful enemy. The Celestial Intervention Agency of the Time Lords attempts to contact the Doctor for help.
The Seventh Doctor rescues a young woman on a distant planet, and prevents the death of a crippled old war criminal. The Fifth Doctor rescues a young woman on a German WWI submarine, and prevents the thing from sinking. The Sixth Doctor insults a young woman at a tourist resort and attempts to rescue a giant sentient legendary exploding time snake called a "Temperon". But they all get locked out of their TARDIS, and they soon find themselves transported to said time snake's vicinity.
It turns out that the Doctors rather accidentally changed time for the worse, and that the time anomalies and resulting wars will feed a group of malevolent Clock Roaches called "The Sirens Of Time". The young woman — who was always the same person, named Lyena — engineered the whole thing. The Temperon sacrificed itself, and chose to live forever in the event horizon of its eternal agony if it would save the universe.
The Sixth Doctor, always the Combat Pragmatist, saves the universe by shooting stuff and setting the Temperon free. The time stream is restored, and the Gallifreyan Celestial Intervention Agency is tremendously confused by none of it having happened to begin with.
- Ascended Fanon: Many of the story's elements are from Nicholas Briggs' unofficial Doctor Who Audio Visuals.
- Bat Family Crossover
- Clock Roaches
- Combat Pragmatist: Lyena believes that the Doctor's eternal compassion will cause him to always be heroic, no matter what. Six reminds her that his particular incarnation is a little bit less compassionate and a little bit more pragmatic. He then simply shoots his way out of the situation and saves the day. Five disapproves, just a bit.
- Continuity Nod: The Doctor references hiking in the Himalayas and complains about companions twisting their ankles. "Contact!" also makes a return.
- Doomed Hometown: The Doctor has this with Galifrey unless he can save it. Ironic, given the new series.
- Distressed Dude: The Fifth Doctor, as usual, gets physically incapacitated. He first gets shot in the shoulder, and then manages to break his leg (and Six's fall) just a few minutes after he meets his later selves. When he decides to stay behind so as not to slow down the others, Six and Seven mock him for being insufferably noble. He then proceeds to get himself captured and tortured, screaming in agony in the (far) background for an entire scene.
- Evil Plan: The Sirens of Time. Basically, they are manipulating everyone in order to create serious changes to the time stream so they can feed off the resulting energy.
- Fanservice: The Fifth, Sixth, and Seventh Doctors all back? Hells yeah! What a way to kick off the series!
- For Want of a Nail: The saving of a common criminal on the Lusitania results in the death of Alexander Fleming, preventing penicillin from being discovered. Without penicillin, humanity was never strong enough to develop space travel, and thus could not eventually raise an intergalactic army to fight the Knights of Velyshaa.
- I Hate Past Me / Future Me Scares Me / Other Me Annoys Me: Completely subverted. Aside from Six picking up a gun readily which irks Five a bit, it doesn't for long. At the end and during the adventure the three Doctors are courteous towards each other, as opposed to the other time three Doctors came together to battle a mutual threat.Fifth Doctor: "Doctor."Seventh Doctor: "Doctor, Doctor."Sixth Doctor: "Doctor, Doctor."Fifth Doctor: "Doctor."
- A Nazi by Any Other Name: Knights of Velyshaa.
- Phrase Catcher: Implied. When Ellie expresses horror at the situation, Six wearily asks if she's talking about his coat.
- Retired Monster: Sancroft.
- "Shaggy Dog" Story: Effectively, everything the Doctors accomplish is undone again by their own actions.
- Translation Convention: Played With. The (Fifth) Doctor speaks fluent German of course, but it's overly "textbook". And the German soldiers are weirded out by the fact that despite his fluency, he somehow sounds like an English gentleman.
- Well-Intentioned Extremist: Sancroft considers himself this. His final speech may have well have been given by the Doctor, with strong overtones of Not So Different.
- Written-In Absence: Since the Fifth Doctor never travelled alone, Tegan and Turlough are just said to be locked inside the TARDIS. Six and Seven seem to be travelling alone during the adventure.