Donal MacIntyre: Unsolved

Donal and his team investigate the disappearance of seven-year-old Daniel Entwistle, who disappeared on a bank holiday weekend in 2003 in the seaside town of Great Yarmouth. They explore the possibility that he may have been the victim of a paedophile ring operating in the area, or may have been the victim of a schoolboy prank which ended in tragedy.

Donal tackles the murder of fifty-year-old supermarket worker and gardener Alan Wood, who was murdered in his own home in Lound, Lincolnshire in October 2009. Theories suggested include the possibility that his murder was a case of mistaken identity, linked to his workplace, or that his involvement with prostitutes may have led him into a murky underworld of sleaze.

Donal once again heads east as he investigates the murder of 16-year-old Natalie Pearman, who was found dead in November 1992 after working the red light district in Norwich. Donal looks into her troubled past in an attempt to discover whether or not Natalie's sordid lifestyle was responsible for her death, or whether she may have been the victim of a serial killer.

Donal heads back to his native Ireland to investigate the disappearance of 26-year-old American student Annie McCarrick, who disappeared on her birthday in 1993 after heading up to the Dublin mountains. Theories proposed include that she may have fallen victim to a serial killer operating in the area, or that her disappearance may have been linked to the IRA.

Donal investigates the disappearance of 35-year-old Claudia Lawrence, who disappeared from the vicinity of her home in York in March 2009. Donal unravels a web of intricate private relationships that could have played a part in her death, and using a timeline of events containing substantial gaps, tries to determine, the exact moment that something sinister took place.

Donal investigates the murder of 62-year-old retiree Barry Rubery, who was attacked and murdered in his own home in Iron Acton, Bristol in October 2010. He explores theories that Rubery may have been killed due to his association with Freemasonry, an angry client he met through his scrap metal business, or may have been the victim of travellers whom he had confronted several weeks previously.

Donal investigates the motiveless murder of 55-year-old Valerie Graves, who was murdered in her sleep during her stay at a guest house that she was housesitting for friends in West Sussex in December 2013. Despite her family having also been sleeping in the house at the time, her killer managed to enter the property uninterrupted and commit the murder without anyone noticing.

Donal takes on the case of 22-year-old Trevor Deeley, who disappeared on 8 December 2000, following his works' Christmas party in Sandymount, Dublin. Evidence suggests he may have been followed on his way home, or may have been the victim of a freak accident caused by torrential weather conditions and the increased number of drunk-drivers due to a taxi strike.

Donal investigates the seemingly motiveless murder of 51-year-old Penny Bell, who was found dead in her car on 6 June 1991, in Uxbridge, near London. Having been stabbed over 50 times, Bell's death appears to have been at the hands of someone she knew. Donal explores the theory that she may have been being blackmailed in the days and weeks prior to her death.

In the last case of the series, Donal heads to Bonhill in Scotland to investigate the murder of 14-year-old Caroline Glachan, who was murdered on 24 August 1996 whilst walking the mile journey to her boyfriend's house. Donal explores the possibility that Caroline may have been a drugs mule, or the victim of somebody who assumed that she was.