20 was a number. As a defence mechanism for the Doctor's TARDIS there were twenty wrong holes within the lock and one right one. Attempting to open the door through a wrong one would cause the lock to melt, preventing access entirely. (TV: The Daleks) The Tenth Doctor made the observation to Richard Lazarus that some people lived more in twenty years than others did in eighty. (TV: The Lazarus Experiment) Behind the scenes Edit According to The Last Dalek, a video game based on the events of the television episode Dalek, Adam Mitchell was 20 years old in 2012. Retrieved from "https://tardis.fandom.com/wiki/20_(number)?oldid=2727446" Categories: Numbers + cat Cancel Save Community content is available under CC-BY-SA unless otherwise noted.