Coming back after a long layoff, it's virtually impossible to recap all the threads left dangling after season one, except to say the amusement park for adults that Michael Crichton conjured — and showrunners Jonathan Nolan and Lisa Joy have cleverly updated for modern times — has imploded in a big way, resulting in an every-robot-for-him-or-herself melee on multiple fronts.Once again, the show oscillates between past and present, filtered in part through the character of the man in black, played with steely ruthlessness by Ed Harris. The newly sentient robots, meanwhile, have their own objectives, and it's the female characters leading the way, most notably Dolores (Evan Rachel Wood) and Maeve (Thandie Newton), who each exhibit an almost-ethereal serenity about the bigger picture and their roles in it."They took our minds. Our memories," Dolores says, hinting at plans to bring her battle from within the confines of Delos to the wider world.Where that will ultimately lead is this season's slow-unspooling mystery, while the human in charge (several of them new faces, for obvious reasons) seek to regain control. In the interim, there's a tremendous amount of bloodshed — blunted in its impact by the fact that some of it feels gratuitous, and a lot of it directed toward characters (a term used loosely, in some places) about which there's little reason to care.Admittedly, "Westworld" overcame initial misgivings about its first-season structure by thoughtfully flipping the script in terms of who the bad guys really were. Instead of renegade robots preying on humans, the show zeroed in on the nascent humanity of these artificial constructs, contrasted with the brutality inflicted upon them by people indulging their darkest impulses and fantasies.When William (Jimmi Simpson) tells Dolores, "You really are just a thing," there's considerable irony in the juxtaposition of his moral decay with her dawning awareness. And when she says later, "There is beauty in what we are," it's an invitation to contemplate what really makes somebody human.The push and pull of "Westworld" is that it grapples with deep intellectual conundrums while reveling in a kind of numbing pageant of death and destruction. Where the latter is organic to the world of HBO's other huge genre hit, "Game of Thrones," it doesn't always feel integral to the story here, but rather a means of killing (and killing and killing) time.As noted, "Westworld" has a genuinely epic quality to it, augmented by the addition of this season's Shogun World; a cast to die for (heck, we haven't even mentioned Jeffrey Wright yet, whose Bernard is one of the more complicated and fascinating personalities); and a demonstrable willingness by its writers to play the long game, in a way that turned first-season fans into amateur spoiler hunters.For all its strengths, though, the series proves a bit of a slog, at times, as the wheels turn along the dusty, blood-specked road to wherever this maze leads."Westworld" begins its second season April 22 at 9 p.m. on HBO.