*Warning: contains spoilers for Unforgotten season four, episode six*
The Unforgotten season four finale delivered an emotional knife twist, following on from last week’s shock cliffhanger.
ITV viewers had previously been left in the dark about the fate of beloved cold case cop DCI Cassie Stewart (played by Nicola Walker in the Unforgotten cast), after she was involved in a car crash right at the end of episode five.
The finale answered the question on everyone’s lips: did Cassie die in the car crash? And was there evidence of foul play, as DI Sunny Khan (Sanjeev Bhaskar) suspected?
Does Cassie die in Unforgotten?
At the start of episode six, Cassie was rushed to hospital to be operated on, and initially the signs looked good.
DI Sunny Khan was among the first to arrive at the emergency ward, later joined by Cassie’s son, Adam; her dad Martin and his girlfriend; and Cassie’s partner John. Her prognosis seemed good, which gave all of them permission to hope, and to look ahead to when life could resume.
When Martin had last seen Cassie in the flesh, he’d turned her away from his doorstep. She had subsequently left him an apologetic, conciliatory voicemail shortly before her car crash. At the hospital, he forgave her everything and quoted the voicemail back to her as she lay unconscious in her hospital bed.
Cassie’s improved prognosis also gave Sunny permission to continue working on the Matthew Walsh murder investigation.
Following up on an inquiry Cassie had made about Dean Barton’s long-dead brother, Stephen, he was able to work out that it was Dean who stabbed Walsh with the fountain pen, as revenge for killing Stephen in a gang dispute.
However, immediately after the solve, Sunny returned to the hospital – only to learn that Cassie’s brain injuries had been far more extensive than anyone had realised, and that she would never wake up.
Spotting a clearly devastated John sat outside Cassie’s hospital room, Sunny uttered a small, heartbroken, “No”.
Martin also rushed outside into the car park, sitting on a bench and sobbing while listening again to his daughter’s final voicemail.
Cassie died, and we saw Sunny lay a bouquet of flowers at her gravestone (inscribed with “Mother, Daughter, Copper”) while his heartfelt funeral tribute to her played as voiceover.
Was Cassie murdered?
Sunny was initially convinced that one of the four Unforgotten suspects had purposefully committed a hit-and-run, hoping to jeopardise Cassie’s murder investigation.
The beginning of episode six definitely hinted at that possibility, as we saw all four of the suspects driving through the dark to their respective homes.
However, in the end it turned out to be a car thief who had crashed into Cassie in a terrible accident. She had pulled out in front of him, distracted and checking her phone for any messages from her father, Martin.
You can read our Unforgotten season 4 ending explainer to learn more about what happened in the finale, including the reveal of who killed Matthew Walsh.