"Anyone can be killed." Words spoken by young Arya Stark (Maisie Williams) in promos for HBO's Game of Thrones, returning for its second season Sunday. And they ring true. Just ask Dustin Hoffman, Nick Nolte, and the crew of Luck. Despite an A-list cast, direction by Michael Mann and scripts from Deadwood creator David Milch, HBO's race track drama was recently shit-canned after reports that a third horse had been killed during filming. A cynic -- wouldn't even have to be very cynical -- could point out that Luck's low ratings may have had more to do with the cancellation than any tender sensibilities about equine health. At this point HBO wouldn't cancel Game of Thrones if it emerged that horses had been eating babies on set. The sprawling fantasy series set in the Seven Kingdoms of Westeros caught fire during its initial season, to the point that buzz over its reappearance almost eclipsed last week's even-longer-awaited return of AMC's Mad Men. Character assassinations Game of Thrones promises to continue its complex storytelling with new characters like Melisandre the red priestess (Carice van Houten), Ygritte the wild woman (Rose Leslie, who played Gwen the ambitious servant girl in Downton Abbey), and many more. George R.R. Martin, author of A Song of Fire and Ice, the fantasy novel series upon which the series is based, recently said, "As fast as I kill characters, new ones come in." Like the girl says: Anyone can be killed. And that helps explain the growing popularity of Game of Thrones. There may never have been a dramatic series so narratively fearless. TV viewers long conditioned to expect that central figures played by big stars do not perish were collectively stunned when the axe came down in season one. Game of Thrones has a core of Martin fans who are eager to see their favourite fantasy series brought to life, but I'm glad I'm not one of them. One of the kicks of the series is the simple joy of not knowing what's going to happen. The other secret of Game of Thrones lies in Martin's deceptively simple breakthrough -- he created a huge, Tolkein-like fantasy world, but peopled it with characters of human scale. Since the days of King Arthur it's been de rigeur that fantasy epics must involve glorious heroes fighting the ultimate battle of Good vs. Evil, and at stake is yada yada yada. I recently watched Excalibur again. Brave knights in shining armour, literally -- they appear to be walking under klieg lights even in mid-forest -- campy swords-and-sorcery, epic quests and, as Merlin, Nicol Williamson chewing the very bark off the trees. The contrast with Game of Thrones couldn't be greater. In the Seven Kingdoms it's all mud, blood, and politics. Dragons too. But Martin didn't make the mistake of letting the magical aspects of his fantasy universe affect the believability of his characters. Fantasy is fine, but moral complexity is essential. It's why Batman is more compelling than Superman. The otherwise unlucky As for Luck, they probably have only themselves to blame. News reports have suggested that the producers ran arthritic old nags until they collapsed. They should have known better. It's a shame -- the show was becoming more compelling as it progressed. But despite the expensive talent it employed, the show's lack of popularity is not that surprising. The problem lay with Milch. A brilliant but famously idiosyncratic talent, Milch has a highly identifiable voice. With Deadwood, the elaborate language spoken by its Wild West characters worked. It sounded like a natural part of the invented culture. Luck was different. The racetrack may have a particular culture, but this was a 21st century story. Yet everybody sounded the same. Different characters, different backgrounds, all speaking with the same odd syntax and backward sentences. When they opened their mouths, all you heard was David Milch. It became claustrophobic -- like spending an hour inside Milch's head. Still, I'm sorry I won't get a chance to see what Dustin Hoffman's Ace would have got up to in a second season. There can never be enough quality drama on TV. So welcome back, Mad Men. And hurry, Sunday. I'm embarrassed at how much I've been looking forward to this. Just a word of caution to Game of Thrones producers -- do try to look after the horses.