Karen Pirie season two ending explained as ITV detective drama returns

After a three-year wait, Karen Pirie has returned to screens with a second season of the ITV detective drama.

The series, which is based on Val McDermid’s Inspector Karen Pirie novels, stars Outlander actress Lauren Lyle in the leading role, as a young, fearless Scottish investigator "with a quick mouth and a tenacious desire for the truth".

The second instalment, titled A Darker Domain, follows Pirie taking on another cold case and uncovering the truth behind dark secrets, lies and a web of potential motives.

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The three-part season exposes the 1984 kidnap of a charming heiress to a vast oil fortune, Catriona Grant, and her two-year-old son Adam.

They were brutally taken and held at gunpoint outside a fish and chip shop in Fife, with the ransom notes leading to an uncontrollable press storm.

But, when the culprits turned to silence and the police failed to secure any leads, Catriona and Adam’s disappearance remained a mystery.

After a man’s body is found with links to the original kidnap, in the first piece of evidence from the case in decades, Pirie and her team work on what could be the biggest case of their lives to find the truth behind the kidnap, amid pressure from Catriona’s father.

“As Karen delves deeper into what happened in the autumn of 1984, political grudges and painful secrets reveal themselves, and it soon becomes clear… the past is far from dead,” the synopsis teases.

Karen Pirie season two ending explained - what happened to Catriona Grant?

In a shocking twist, we discover that Catriona (played by Julia Brown) was involved in her own kidnapping.

In a bid to punish her own father Brodie (played by James Cosmo) after discovering he had used Fergus (John Michie) - Adam’s secret biological father - to cover up how his oil operations had resulted in deaths, Cat and her boyfriend Mick (Mark Rowley) set up a fake kidnapping.

She wanted to start a new life with Adam and run away with her father’s money, but her plans were brought into disarray when Mick’s friends Andy and Kevin were pulled into the plan. Mick, untrustworthy of Kevin, wanted to hide the fact that Cat was involved in the kidnapping, and debated with her whether they should tell Kevin the truth.

When Kevin overheard their argument, he threatened Cat that he would tell Brodie the truth, so Cat shot him in the head, killing him. His body was the one found decades later, sparking the opening of the investigation.

But his remains weren’t the only ones found. Pirie’s team found Cat’s body in a cave, with viewers soon learning that her mother, Brodie’s ex-wife Mary (Frances Tomelty), had been the one to kill her after an emotional confession.

Fergus and Brodie had discovered that Cat had plotted the whole kidnapping, and arranged to meet Mick, Andy and Cat and handover the money, but Mary had followed them with a gun, intending to scare away the real kidnappers without realising her daughter had known the entire time.

When she reached the cave, she shot twice, mistakenly killing Cat and causing the cave to crumble, leaving her trapped inside.

Mick, Andy and Adam escaped, while Brodie and Mary kept the truth a secret for decades, in the hope that Cat had remained alive all along.

They weren’t the only ones to discover the truth however, as Adam, re-named Gabriel after Mick raised him in Italy, learned who he really was and about his biological father and mother.

The case ends with the arrests of Mary and Brodie, and Adam meeting his biological father Fergus, who is also on trial, but choosing to continue living his life with Mick in Malta, as he couldn’t be reached by the Scottish authorities there.

“There’s no joy in closing a case like this, no joy, no celebration,” Karen is heard saying as the show ends.

“Because my job is about finding answers, and I hope those answers bring peace.

“But sometimes they aren’t the answers that anyone wants to hear, people aren’t who you expect them to be, victims don’t always fit the ideal narrative.

“Money and power can help you re-write history until even you believe it, but [in the end] everyone needs the truth, so I’ll keep looking for it.”

Karen Pirie is available to watch on ITVX