The veteran drama continues its 14th series. In this week’s episode, an Iranian businessman is murdered the day after his wedding to a much younger woman. The investigation focuses on the widow, before turning to the victim’s daughter, who harboured a series of grievances against her father.

Detectives Briscoe and Green are called to an expensive townhouse where successful Iranian caviar importer Mr ‘Mani’ Soleimani has been found dead in bed. The ME reports that Mani is barely cold, but cannot establish cause of death without an autopsy. When Green hears that the 68-year-old old had just wed his 25-year-old bride, Yasmin, the day before, he thinks he has a possible explanation: “Young bride, old groom, wedding night – maybe he died of a heart attack?”

Mani’s son, Ben, is convinced that it was murder, but Yasmin believes her husband died of natural causes and wants him buried within 24 hours, in accordance with their religion. The cops manage to circumvent the widow’s wishes by convincing a judge to order an autopsy. Sure enough, the ME finds that Mr Soleimani was tranquilised before being smothered to death. The only other clue is a foreign hair on the dead man’s chest.

A murder investigation gets underway, but Briscoe and Green are faced with a long list of suspects. The young widow is the first to come under suspicion, but she is discounted when her alibi checks out. The cops then turn to one of Mani’s rivals in the caviar business, before investigating his son, Ben.

The cops learn that Ben may have had a motive to kill when they hear that he was gradually running the caviar company into the ground. “If Ben was wrecking his father’s business, he might have been worried that the old man would take it away from him and leave it to the new wife,” Briscoe says. In which case, Ben called 911 simply as a “smokescreen” to cover his evil deed.

However, when forensics establish that the murder weapon was a pillow belonging to Mani’s daughter, Roya, a new suspect enters the frame.

Southerlyn soon discovers that Roya had plenty of reasons to hate her father. It transpires that she is unable to have children after injuring herself in a horse-riding competition as a teenager – a competition that she entered at her father’s behest. Later on, she and her husband, Asher, tried to adopt a Chinese baby, only for Mani to order her to abandon the idea. “If Roya had disobeyed her father, she would have been ostracised,” says the family rabbi.

Mani and Roya lived together for almost 20 years following the death of her mother, sharing the house almost as a married couple. Even when she married Asher, Roya continued to live with her father, acting like a “surrogate wife”. But with the arrival of Yasmin, Mani asked his daughter to move out – a final insult in a string of injuries. When police learn that Roya had a prescription for the drugs that tranquilised Mani, and the hair on his chest matches her DNA, the case falls into place. “Everything points to her,” Southerlyn tells McCoy.

At the trial, Roya appears to be doomed by weight of evidence against her. But just when it seems her cause is lost, Asher takes the stand and stuns the court by confessing to Mani’s murder. “I was devoted to Mani as if he were my father, but in the end he betrayed the convictions he claimed to live by,” he declares. McCoy is incensed by Asher’s confession, accusing him of lying to protect his wife. But with the case thrown into confusion, will the real killer go free?