Our take
The fifth Christmas special has the best hook of the run so far: a shooting in a Caribbean pool with a gun that was locked in a drawer in Swindon at the time. The office-party suspects bring plenty of broad comedy and a little grey English winter. The real heart is Mervin, lonely and short-tempered at Christmas, slowly letting his team in, and a welcome return for an old favourite lifts the last act.
What happens
Months after reaching out to the half-brother he only recently discovered, DI Mervin Wilson has heard nothing back, and with Commissioner Selwyn Patterson gone from Saint Marie he is in no mood for Christmas, even with a part to play in the island's annual nativity. Helen Dugdale, managing director of a branded merchandise company in Swindon, has flown her team to a Caribbean villa for the office Christmas party as a reward, leaving receptionist Marjorie Dodds behind. The morning after, four of the co-workers wake with crushing hangovers to find a stranger, local fisherman Darrian St Jules, shot dead in their pool, with the reindeer name Blitzen written on his palm. All of them, including head of sales Karen Hickson, her partner Gavin Bradbury and Helen's son Neil, say they never met him. Mervin, DS Naomi Thomas and Officer Sebastian Rose identify the gun, only to find it was locked in a drawer in Swindon, thousands of miles away, when he was shot. Ashley Simms, who left the company under a cloud months earlier, also comes into the picture. As the case pulls them into a web of secrets, the now retired Selwyn, spending Christmas in the UK, is persuaded to help. Mervin loses his temper with Seb over a blown budget, later makes amends, and invites the team to his home on Boxing Day; at last he gets through to his brother on the phone. The special also confirms that Selwyn will take his old job back.
Can the kids watch it?
No BBFC rating found for this special; the earlier specials were rated 12, and with a shooting at its centre it suits children from about 12.