Well, doesn't that just say it all?! Brian Williams has established himself as one of the most popular characters in Doctor Who history which is quite an achievement when you consider the fact he's only appeared in two episodes. It was all he needed to become a firm fan favourite, though, after being introduced in Series 7's Dinosaurs on a Spaceship as Rory's simple but doting father who accompanied the Doctor & Co on an adventure which subsequently inspired him to travel the world, much to the dismay of Rory and his daughter in law, Amy, who quickly built up an impressive collection of his homemade postcards. Brian was also on hand to aid our heroes by watching the Shakri cubes ('watch' being the operative word there!) during The Power of Three's Year of the Slow Invasion and he well and truly kept it in the family when he became the Doctor's grandfather in law following the Time Lord's marriage to Amy and Rory's daughter, River Song. It all escalated very quickly and it still doesn't make a whole lot of sense. Still, Brian's story was left open after the Ponds' untimely departure in The Angels Take Manhattan but he was granted his own happy ending (of sorts) in the form of an animated epilogue, P.S., which gave him the closure he well and truly deserved. Someone's got to stay behind and water the plants, right?