After six weeks of suspense and scandal, The Undoing has finally revealed the truth behind its shocking mystery.
Nicole Kidman and Hugh Grant lead the cast of Sky Atlantic's glossy crime drama, which follows a wealthy couple at the centre of a brutal murder investigation.
Over the course of the series, several suspects have emerged and a number of twists have left viewers with their jaws on the floor, with many taking to social media to speculate.
We shared our own The Undoing theories last week, but now it's time for the truth. Read on for full spoilers from the series finale.
The Undoing ending explained: Who killed Elena?
Given the stacks of evidence mounted against him, it should come as little surprise that it was Jonathan Fraser (Hugh Grant) who committed the horrifying murder of Elena Alves (Matilda De Angelis).
At the end of episode five, Grace found the murder weapon (a sculpting hammer) in the bedroom of her teenage son, Henry, which led to speculation over whether he could have been capable of such a despicable act.
However, the boy quickly explained he had found the hammer at the family beach house, which he, Jonathan and Grace had fled to when the accusations first went public.
From that moment onwards, Henry was certain that his father was the culprit behind the murder, but felt compelled to protect him in order to prevent his family from falling apart.
So, he took the hammer and cleaned it in the dishwasher twice to remove any DNA evidence, before hiding it in his violin case and keeping its whereabouts secret to everyone.
When Grace told Jonathan the hammer had been discovered, he maintained his innocence and even tried to shift blame onto his young son, proving there are no depths to which he was unwilling to sink.
It was at this point that Grace lost all faith in her husband, but she was in a difficult spot: declare the weapon and her son could face prison time for obstruction of justice, but refuse and Jonathan could unjustly walk free.
In a sharp move, she chose to take the stand and during her examination by the prosecution, she revealed the disturbing account that Jonathan's mother had told her about the demise of his sister.
The prosecuting lawyer effectively convinced the court Jonathan has narcissistic personality disorder, owing largely to his arrogance and lack of empathy, all but guaranteeing a guilty verdict.
In flashback, we saw that Jonathan did murder Elena with the sculpting hammer after unsuccessfully attempting to end his affair with her.
In a final desperate bid, Jonathan attempted to flee on the morning of his verdict, taking his son as a captive, but was ultimately apprehended by police.
The series ended with Grace and Henry finally breaking free of Jonathan's toxic grip, with some hope of putting this terrible trauma behind them once Jonathan is behind bars.
Is The Undoing ending different in the book?
The Undoing is based on You Should Have Known, a novel by author Jean Hanff Korelitz, which does vary in some ways to the television adaptation.
However, the murderer is the same: Jonathan is again the guilty party, although his crimes are exposed rather differently.
In both stories, Jonathan flees after committing the murder, but in the novel he remains in hiding for the entire story, ultimately confessing in a letter sent to Grace from an undisclosed location.
However, key plot points such as his affair with Elena and his responsibility for a younger sibling's death remain the same, while Grace's story also ends with her leaving her old life behind and getting a fresh start.
The Undoing is available to stream on NOW TV. Looking for something else to watch? Check out our TV Guide.