Red Hatching was an event that the Tenth Doctor and Martha Jones faced in 2008 or 2002 (AUDIO: Recruits, Salvation), armed with just a bow and a quiver of arrows. They were running to it when Sally Sparrow gave the Doctor the information of the TV conversation that they would have in the future. Red Hatching involved "four things and a lizard". (TV: Blink)
The event resulted in Cleo Proctor's father getting killed by the alien inside the egg, with the Doctor only arriving moments after to save Cleo. Cleo Proctor re-discovered this blocked memory in 2022 while going through the Thirteenth Doctor's mind. (AUDIO: Salvation) Before this, she had believed her father had disappeared nearly twenty years prior. (AUDIO: Recruits)