The Affair knows that it is retreading well-worn ground. Adultery has been covered so extensively across all forms of media that it’s hard to imagine a new TV drama adding much to the conversation. For the first few episodes, though, it seemed like Sarah Treem and Hagai Levi had achieved the massively unlikely. The show actually felt original, with a fresh angle on its main characters and an innovative storytelling style. It’s unfortunate that by the tenth and final episode of the season, that freshness had all but disappeared into the many clichés of infidelity fiction.

The Showtime drama follows Noah Solloway (Dominic West), a high school teacher and novelist who begins an affair with waitress Alison Bailey (Ruth Wilson) during a summer in Montauk. Both Noah and Alison are married, but they waste no time—by episode two their romance is already underway. As you would expect, all does not go smoothly. Each member of the couple has their own personal issues to work through, with Noah feeling career pressure from his wife’s wealthy family and Alison still grieving a recent tragedy. On top of that, their respective spouses, Helen (Maura Tierney) and Cole (Joshua Jackson), soon start to notice their other halves seeming more distant than usual.

None of this is new material. The Affair‘s initial appeal came from its structure, rather than its fairly typical content. Each episode is split in two halves, with one told from Noah’s perspective and the other from Alison’s. We see early on that they are recounting the story of their relationship to a detective in an interrogation room, as part of an investigation into a mysterious death. This means that we are constantly seeing not their present tense experiences but their memories of events that transpired (presumably) multiple years ago. Small differences in their recollections therefore take on more significance: even changes in clothing reveal interesting details about the central characters. In Noah’s memory of their first meeting, for example, he sees Alison in a sexy dress, acting like a stereotypical temptress. In Alison’s version, she is wearing an unflattering work apron and no make up, and is certainly not out to seduce anybody.

The central performances are strong, although both lead actors are British and their American accents are far from perfect. West brings a slight sleaziness to Noah that works, and Wilson manages to be both vulnerable and crafty. Tierney and Jackson are also really excellent—if anything, they are underused. When problems develop with The Affair‘s first season, writing and plotting begin to let this cast down.

Lead characters do not have to be likeable to be good, so the fact that Noah and Alison are almost entirely unsympathetic is not really the issue. It’s more that their unpleasantness is paired with uninspiring action. In great dramas like The Sopranos or Mad Men, characters might be flawed and even cruel or violent, but they are usually at least doing interesting things. Noah and Alison, on the other hand, have few redeeming qualities and are shown having what seems like a very typical adulterous relationship. The result is therefore boring and pretty much free of emotional engagement; Tierney succeeds in making me care about Helen, but since she is only ever shown from Noah or Alison’s perspective (neither of which is particularly flattering, for obvious reasons), she doesn’t get much screentime and has little to do. When big emotional moments do come her way she knocks them out of the park, but they are much too few and far between.

Things get even worse when The Affair seems to realise that it’s edging towards being dull. Treem and Levi respond by ramping up the mystery and criminal elements of the show, bringing in ludicrous murder and drugs sideplots that completely negate the apparent initial intention to show the effects of infidelity on pretty ordinary people. Suddenly the show is less about the limitations of memory or the consequences of cheating and more about cocaine dealings, which doesn’t actually solve the boredom problem at all.

I don’t want to spoil anything, but I will say that in the season finale there are two musical montages within the first ten minutes of the episode, and they’re so clumsy they may as well have shots of calendar pages being ripped away. I had high hopes for this show, and these segments demonstrated exactly how it disappointed me. What could have been a clever and careful look at cheating became a mess of clichés and lazy melodrama.

Grade: C+

Should have been a miniseries.