The sentry turret is one of the most quoted characters from Valve's Portal games, where a polite childlike voice sells the absurdity of a security robot that apologises while aiming at you. Turret voice lines have been ripped, remixed and memed for years, with Ellen McLain's gentle delivery making even the shortest ones instantly recognisable. This brief goodnight clip circulates on soundboards as a tender sign-off rather than a threat, the joke being that the game's friendliest killer is tucking the listener in.