Still in 1969, the Doctor has come to the conclusion that the alien creatures are only seen when they directly look at them. As soon as you look away, any memory of their presence is wiped clean. The aliens are also able to leave suggestions in people’s minds, and aren’t invaders per se, but have been on Earth for a very long time. While the Doctor works to ensure the success of Apollo 11, the others try to solve the mystery of the little girl in the space suit.
Watch It Here : Doctor Who Season 6 Episode 3