After Katherine calls Damon with a tip that Stefan and Klaus are in Chicago, Elena and Damon head out on a road trip while Stefan takes a trip down memory lane into memories he never knew he had.
Back in the 1922, Chicago was a magical city and Stefan was still known as "Ripper". It was in a small, swinging club where Stefan first encountered two Originals, Rebecca and her bother Klaus. During this time that Stefan became close with the two of them and even taught the hybrid vampire a few tricks of his own. Back in the present, Elena and Damon are on their way to Chicago with a plan to save Stefan and with any luck, not get ripped apart by Klaus in the process. Meanwhile in Mystic Falls, Caroline's father is determined to drive the vampire out of her or kill her if necessary. After Elena and Damon arrive in Chicago, she's forced to confront more of Stefan's unsettling dark past and may have to accept that she has lost Damon forever.
Simply put, The End of the Affair is the best episode of the season thus far. Whereas many other shows use flashbacks to explain an aspect of a character or the history of an event, The Vampire Diaries seamlessly weaves the past directly into the present. Each scene with Stefan and Klaus in 1922 provided a great insight into each of the characters and especially Klaus's relationship with Stefan. As Klaus has often referred to Stefan as his comrade and brother it was great to see how that came together. Rebecca was also integrated into that story in a very organic way and how she will play into Klaus's pursuit of creating an army and whether or not she will be forced to choose between her brother and Stefan once more will be very exciting.
An aspect that I often comment on in The Vampire Diaries is how unfocused the show can often seem. Whether this is due to how many characters the show has or how many storylines are going on at once, it can often lead to an over packed episode; that was not the case this week. Even though there was a focus on Damon and Elena, Stephan and Klaus and Caroline and her father the pacing and tone of each story was consistent. The show did not jump from the usual life and death situation with Elena to crazy party that Caroline had organized at the Mystic Grill to take us completely out of the moment established just moments before. It's often difficult to make this happen on a weekly basis but this episode would have suffered greatly if Matt, Jeremy and Tyler (in a larger role) were also included with their own stories to tell.
The End of the Affair left little to be desired in an episode from The Vampire Diaries. Now that Caroline's father is determined to "fix" her and there is another Original returned from the grave, the show could be on a new path starting in next week's "Disturbing Behavior".