While the fourth season of Arrow hasn't been on the same level as the previous seasons as a whole, there are absolutely amazing individual episodes in the mix. A good example is Sins Of The Father, quite possibly my favorite episode of this season so far. It does a good job combining the best characters, story lines and other elements of the series, resulting in a powerful and memorable episode.
Malcolm Merlyn has always been the most intriguing and well-written character on Arrow - or in the whole CW/DC television universe for that matter. The way the character is constantly flailing between good and bad, trustworthy and betraying, likable and frustrating, all of that just makes him into such a great character. And this episode highlights that, as John Barrowman gives his best acting performance so far and his character becomes even more fascinating. All of his scenes here are pure gold, and that alone makes the episode stand out.
In a bigger picture, the episode succeeds on more levels than just utilizing one amazing character. There's also the drama with Thea's life hanging in the balance, intertwined with the League Of Assassins descending to the brink of a civil war. I won't give away any specific plot details, but many of the story lines that have been building up for multiple seasons come down to a boiling point. The rivalry between Nyssa and Merlyn makes for a fresh break from the episodes focused on defeating Damien Darkh and his people. Towards the end of the episode, we are also treated to one of the best fight scenes in Arrow history, as two major characters duel one another. The directing, choreography, acting, soundtrack and everything else about that scene is just breathtaking.
In an even bigger picture, this episode deals with a large theme - fatherhood. This is accomplished in many ways from many directions: Merlyn doing anything in his power to save his daughter, Felicity's father trying to reconnect with her, and even references to Oliver's son William and their distant relationship. Also Nyssa going up against her father's legacy goes together with this theme. 'Sins Of The Father' as a title describes the episode quite well, as many of the father-characters do questionable things with more or less good intentions, giving a conflicting view on the subject.
The episode ends on a brutal twist that I won't spoil here. I partially saw it coming, but not in a bad and predictable way, rather a slow-burning "It all lead up to this moment" way. I am excited (and slightly terrified) to see what follows from here. All in all, this episode shows season 4's full potential, and hopefully we'll have more like this towards the end of the season. I can only keep guessing what Darkh is planning for next, and I'm definitely looking forward to seeing where Merlyn's character arc goes from here.