The game is set in the orbit of the planet Siralos, one of the Seven Thousand Wonders of the Galaxy. Siralos is composed entirely of malleable psychic energy, which has been hijacked by the Master, allowing him to physically merge his Tardis with the Doctor's.
Both the Doctor's Tardis and the Master's Tardis feature a variety of different environments, where you may find objects the Master sends you to retrieve, puzzles that need to be solved, and power rods to replenish your own energy. You are the Graak, an energy-dependent, amorphous plasma matrix with telepathic links to the Doctor. It is your mission to release each incarnation of the Doctor, one at a time, via intelligent gameplay, physical and mental dexterity, and some working knowledge of Doctor Who mythology.