Bywater was the Security Commander in the Vault, Henry van Statten's underground bunker. Charged with overseeing the Dalek on its escape from the Cage, he sent one of his officers, De Maggio, on escort detail, to ensure Rose Tyler and Adam Mitchell's safety, before engaging in combat - and was the first of the Vault staff to be exterminated by the Dalek's reactivated gunstick. (DW: Dalek)