All good things come in threes, it seems. This holds especially true in the case of the Hemsworth brothers. Two talented, charming Australian actor siblings must beget a third.HBO's Westworld premiered last night , introducing us to the final third of the Hemsworth trio: Luke.Chris and Liam Hemsworth have cemented their roles in the pop culture canon via fan-favorite franchises — Marvel's Avengers and The Hunger Games, respectively. Beyond that, Chris Hemsworth has wooed the world with his enviable dad skills , while Liam Hemsworth's friendship with Jennifer Lawrence continues to be fodder for late-night talk shows. (Not to mention his storied relationship with Miley Cyrus .)So naturally, the appearance of a third Hemsworth is very exciting news. Luke has been hiding in the wings for a while now. Like Casey Affleck or Haylie Duff before him, he's been around, but he hasn't really made a lasting impression. The eldest of the three, Luke Hemsworth has worked as an actor since the early-aughts. (He first appeared in the Australian sitcom Neighbors in 2001.)In Westworld, the eldest Hemsworth portrays Stubbs, head of security at the theme park from which the show derives its name. The series has so far received positive reviews — it has a score of 84% on Rotten Tomatoes . As Westworld is HBO's next big-budget series, reviewers have already been comparing it to television juggernaut Game of Thrones . This certainly bodes well for Luke Hemsworth, who may finally have his own shot at an American hit.