This British Crime Drama Will Challenge Everything You Think You Know About Memory

It takes a great deal of work to even determine who the murder victim is of the case that Detective Chief Inspector Cassie Stuart (Nicola Walker) and Detective Sergeant Sunny Khan (SanjeeV Bhaskar) are trying to solve. That's the kind of show that Unforgotten is, making its US premiere on April 8 as part of Masterpiece on PBS. The series, originally airing on ITV, takes each case step-by-step, focusing on elements most other shows would skip over. As the first season proceeds, the details of what happened to Unforgotten's Jimmy Sullivan (Harley Sylvester) after his disappearance in 1976 are slowly revealed. But the way in which these revelations occur raise some major questions about memory and identity.

Major, huge spoilers for Unforgotten Season 1!

After discovering his identity, police manage to track down a diary of Jimmy's. And over the course of his journal he mentions four names. Soon, government official Sir Philip Cross (Trevor Eve); the charitable Lizzie Wilton (Ruth Sheen); Robert Greaves (Bernard Hill), the priest; and the elderly Eric Slater (Tom Courtenay) — who spends his time taking care of his Alzheimer's-afflicted wife Claire (Gemma Jones) — all wind up in the crosshairs of the investigation. While the first episode slowly begins to pick away at the identity of these four important characters, details about what really happened to Jimmy are few and far between. It's clear that Jimmy is dead and that he may have been involved with some rough stuff, judging by how quick everyone is to deny knowing him. But answers to the who, what, where, why, when, and how of his suspected murder seem far off. However, those who want to get the answers now don't have to wait at all because the series already aired back in 2015 on its original network.

The truth about what happened to Jimmy isn't revealed until late in the series, and it hits like a ton of bricks. Because the forensics lab can only do so much with a body that has been rotting for four decades, any useful information about Jimmy is only attained by what the suspects and persons of interest are willing to share. The episodes leading up to the finale aren't as much about collecting physical evidence as they are about interviewing and interrogating these key four people and waiting to see which one of them finally cracks. In the end, however, it turns out the killer isn't one of the four suspects. The killer is Eric's wife, Claire, who beat Jimmy Sullivan with a hammer after she discovered his affair with Eric.

One of the most obvious and present themes in Unforgotten is memory, so it's tragically fitting that the woman who murdered not only Jimmy, but another lover of Eric's as well, likely can't remember committing such heinous crimes. Eric reveals to the police that he had spent most of his life in the closet, and that Claire had murdered his male lovers. Postpartum psychosis following the birth of their child was possibly a factor. While it was Claire who did the physical act, Eric is the one who ends up going to prison as it would be near impossible to convict Claire in her deteriorating mental state.

And that conclusion leaves the audience with a difficult question: is this fair? Is it just for Eric to be sent to jail for a crime that he didn't commit but was complicit in covering up? Should Claire have been given a harsher punishment despite having Alzheimer's? Is Claire still the same person who she was when she murdered Jimmy Sullivan, considering she has no memory of it?

Throughout the series, it's shown how the four people mentioned in Jimmy's diary transformed, and barely resemble the people they used to be — but can anyone ever change enough to free themselves of their past wrongdoings? These are heavy questions to tackle in a whodunnit series, and it's a depressing note for a season to end on. But Unforgotten continued on ITV, and hopefully American audiences will have a chance to follow the next case if PBS also picks up Season 2.