18 September

On 18 September, 1945, Albert Einstein was accidentally transported onboard the Eleventh Doctor's TARDIS while experimenting for his own time machine. After he was briefly turned into an Ood, the Doctor returned him. (TV: Death Is the Only Answer) It was also the day in 1909 when the Tenth Doctor and Martha Jones departed the Lake District after vanquishing the Zygon warlord Brelarn's plan to assassinate King Edward VII. (PROSE: Sting of the Zygons)