The Master is back and this time he will not fail! He has recruited Davros and what is left of his desperate Daleks. Since being beaten by the Movellans, this group of Daleks have nothing to lose. And both have one enemy in common...the Doctor!
The Master has found an ancient Gallifreyan Laboratory equipped with an everlasting self-regenerating "Time Expander". This Time Expander can take any part of time and space, stretch it, then allow all other space and time events to interact with this new time stream. This machine requires two operators to work together (changing time and space is serious business). Of course, this has never stopped the Master, or even Davros.
The problem of finding all seven Doctors and expanding their time streams is easily solved in one word - Earth! This is the Doctor's favorite planet. All of his regenerations past, present, and even future, have or will, arrive upon Earth. All that has to be done is to expand Earth's time and push all the Doctors into the final nova of the Earth's Sun. At game start, you can experience the time expansion of Earth by observing the continental drift back to the past (over 300 million years ago!).
But everything has not gone as planned. All of the Doctors, aware of time being expanded, have escaped. However, not everyone is safe. The first Doctor has escaped to a planet and is being bombarded by the Master's "borrowed and enhanced" Roni spheres. The second Doctor is lost in a land mine of black holes in space and is trying to dodge destruction (the black holes are rumored to power the Time Expander). The third Doctor is trapped in the Whomobile. The fourth Doctor is stranded somewhere to repair his old unreliable force field projectors. The fifth Doctor, transmatted away from Earth is, unfortunately, held prisoner in a never ending transmat web. The sixth Doctor was jettisoned to a mountainous Dalek planet, where the time expanded rebirth of the Dalek race is about to begin. Last but not least, the seventh Doctor is much more fortunate. He escaped unharmed and has found the Time Expander. Now the challenge is to restore Earth's Time to normal, confront the Master and his traps, the Daleks, and of course Davros (the creator of the Daleks).
When it is time for the ultimate battle with Davros, all the Doctors will be re-united, combining their unique knowledge and experience to defeat Davros and his Daleks.