Conjunction
From Tardis Wiki, the free Doctor Who reference
According to a life story told by Astrolabus to the Sixth Doctor, and which the Doctor did not believe, a conjunction of planets in the skies of Earth, which had been predicted by the royal astrologer, turned the city of Alexandria into a crossroads in Time, allowing the Visitors and their skyships to descend into the city from the future. (COMIC: Voyager)
