In a university on planet Sweeney Earth, Paul and Arlene Cole have designed TITAN -- designed to penetrate the vortex and access the very foundations of reality. The Master, who is being pursued by the Chronivores, thinks that TITAN could be the perfect means of revenge...Mel's old friend Anjeliqua also works at the university and the Master charms her into giving him access to TITAN. He recalibrates its settings and locates the Quantum Archimage, the power source of the Chronivores. When this energy is channeled into Anjeliqua herself, she is transformed into the Quantum Archangel, the living embodiment of the Chronivores' power source. With her new-found power, her plan is to "make things better. For everyone".
If she goes ahead, reality will begin to fracture, as conflicting realities struggle to coexist. Otherwise, when the Chronivores detect the alternate timelines, they will consume every last bit of it. Can the Doctor intervene before the universe disintegrates?