Doctor Who Arc of Infinity

Omega an ancient Time Lord made of pure antimatter once defeated by the Doctor is plotting to cross over into this dimension by bonding with the Doctor Meanwhile the disappearance of a man in Amsterdam piques the curiosity of his cousin Tegan who previously left the Doctor at Heathrow Airport and now finds herself at Omegas mercy Fearing total destruction from the collision of matter and antimatter the Time Lords recall the Doctor to Gallifrey to undertake the only viable solution executing him