Nicole Kidman and Hugh Grant lead The Undoing finale, but who is the killer behind Elena Alves’s brutal murder? Spoilers ahead!

But her reality falls apart after when a new mum at her Henry’s elite private school is murdered and Jonathan subsequently goes missing.

Grace seems blindsided by his disappearance and appears equally shocked when detectives tell her that her husband had been dismissed from his job after disciplinary action over “inappropriate contact with a patient’s relative”.

Grace had previously met Elena at a committee meeting, and later ran into her in the gym changing rooms where a naked Elena got a little too close for comfort.

The pair also shared a swift kiss in the lift on the night of Elena’s murder. After her death, we see that Elena had painted a detailed portrait of Grace, which was found in her studio.

While we know Grace alerted the police the moment her husband came out of hiding and revealed himself to her on the veranda, we also see her standing by him – and holding his hand – as he attends his trial.

CCTV footage located by police showing Grace walking the streets just a block from Elena’s studio – where she was found bludgeoned to death with her own sculpting hammer – is yet to be explained.

Grace says she was just going for a walk but can’t actually remember being there. Could her motive have been more sinister?

As the drama’s lead protagonist, we see everything from Grace’s perspective, but is she as reliable a narrator as we think?