*Warning: spoilers ahead for Grace episode one*
The opening episode of ITV's crime drama Grace is claustrophobic viewing, to put it mildly.
Based on the Roy Grace books, the feature-length episode one follows our hero, detective Roy Grace (John Simm), as he races against time to find property developer Michael, who disappeared halfway through his rowdy stag-night.
Michael had off-shore accounts in various tax havens, meaning he could well have got cold feet and decided to run off, leaving his wife-to-be, Ashley, at the altar. But it turns out that something far more sinister is at play.
Grace episode 1 ending explained: What happened to groom Michael?
In Grace episode one, it soon becomes clear that our groom-to-be had been the subject of a dangerous stag-night prank: he had been buried alive inside a nailed-down coffin, with only a small rubber breathing tube keeping him alive.
His drunken groomsmen fully intend to dig him up after an hour beneath the ground, but shortly afterwards they are all killed in a car crash - meaning the nature of the prank, and Michael's underground location, seemingly died with them.
Where was Michael buried and did he survive?
There is one groomsman who didn't die in the car crash, and who also knows the location of the coffin: Michael's best man and business partner, Mark.
Mark not only doesn't tell the police about the location, but he goes back to the wooded area and takes the breathing tube, leaving Michael in even further jeopardy.
Mark's motive? Ashley, Michael's fiancée, whom Mark is besotted with. And it turns out that Ashley (who at the start of the episode played the role of grieving bride-to-be perfectly) has been sleeping with Mark, and knew about his plan to steal the breathing tube.
The police eventually find the coffin in a wooded area; but to Mark's horror, the coffin is empty, meaning someone else out there knows what he did - and that Michael could still be alive.
Sure enough, Mark is sent covert photos of him removing the breathing tube; a demand for £5 million; and, at the bottom of the envelope, a severed finger belonging to Michael.
Mark is then killed by the mysterious blackmailer - and now all eyes turn to Ashley, who isn't all that she seems. She and her real partner (the blackmailer) have been systematically scamming wealthy men across the globe, and Michael was the latest in a long line.
Master manipulator Ashley was supposed to marry Michael and then kill him off a few months later, inheriting all his wealth - but the coffin prank scuppered that plan, meaning that she had to improvise.
Grace catches up with her and her partner as they're about to flee the country, having left Michael to die in a derelict house. Ashley kills her partner and tries to tempt Grace to run away with her, before tricking him into revealing how his wife Sandy's disappearance made him feel.
In the end, Michael is found alive and rushed to hospital - and he has yet to learn about his fiancée Ashley's treachery.
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Grace TV vs the books: How was the twist different?
In the first of the Roy Grace books, Dead Simple, the reader knows from the first chapter that Michael is trapped inside a sealed coffin. However, series writer Russell Lewis (Endeavour) exclusively told RadioTimes.com why the TV adaptation delayed that big reveal.
"With the novel, that hooks you in the first chapter, really," he explained. "But it was such a big thing for us, I think, that it felt like something we needed to earn, to find out what had happened to Michael. So we sat back on it, and allowed the audience to get to know [Roy] Grace a bit, through the device of 'Michael's been missing'. What we didn't want to do was put the audience ahead of Grace, you know?"
He continued: "If you'd known right from the off where Michael was, for those first two parts, it would have had Grace running to catch up with the audience, and I think just in narrative terms you want to be following your hero, finding out things when he finds them out rather than being ahead of him. So that was our thinking on holding back on that... That's our big reveal."
Asked whether he worried viewers might be put off by the horrifying scenes inside the coffin, Lewis said that he approached the source material as "responsibly" as he could, especially for a pre-watershed audience.
"People's stress levels vary but we certainly approached it as responsibly as we could," he said, before adding: "You know, as responsibly as you can approach a book with that in it. It's not something we could have left out. At least we delayed people finding out what was afoot for half an hour, so they've only got to bear it for 90 minutes."
Grace will return later in 2021 on ITV. If you want to start reading Peter James' Roy Grace series, you can purchase the first three novels on Amazon.