|Edition: || UK (VHS)|
|Released: ||March 1994|
|Publisher: ||BBC Video|
|Format: ||1 x VHS PAL|
Shielded by a collapsed star, lurks a malevolent presence, an alien consisting of pure anti-matter. Its intention? To bond with a Time Lord and so cross over into this dimension through the Arc of Infinity — the gateway to all dimensions.
Suddenly, the Doctor finds himself under attack and the TARDIS recalled to Gallifrey where he is put under sentence of death by the High Council of Timelords. For the bonding must be prevented at all costs.
Once there, the mystery deepens. How could the alien have gained the vital biodata extract necessary to carry out the bonding? Is there a traitor amidst the Timelords? What is the link between the alien and Tegan's cousin's disappearance in Amsterdam? Just what is the identity of the shadowy alien — have he and the Doctor met before?
The Doctor must find the answers — and quickly. It is not just his life at risk. If the bonding is completed, it could cause the collision of matter and anti-matter and the destruction of all dimensions...
Originally transmitted 3 - 12 January 1983, this 4 part adventure sees Colin Baker's first ever appearance in the programme as Time Lord Security Commander Maxil and the return of the Doctor's old enemy Omega, whom he originally encountered in The Three Doctors.