The revelation of another ship involved in the killings leads Karsten to investigate illegal fishing in the Seychelles - but he also uncovers evidence of drug-related crime.
A review of the 2016 season, which saw the likes of Shane Byrne and Leon Haslam compete for the title.
MCE British Superbikes
A camera crew documents polar bears in the subarctic, revealing the impact human activity has had on them and revealing how they survive on the ice floes by hunting fish and seals.
Polar Bear Invasion
Children's animation following the adventures of a family of puffins living on a wild and beautiful Irish island. Narrated by Chris O'Dowd.
Part one of two. Abby hits a major roadblock with the group routine, while a former ALDC dancer considers visiting her old team-mates.
As the Winx take a group of lemurs back to their natural habitat, a sudden attack by Kalshara and Brafilius transforms all the bananas into monsters.
Dallas Campbell uses science to reveal the humiliating and painful potential of accidents involving swinging on a trapeze and taking a toy car off road.
Science of Stupid
Action from the second day of the first round of the Triathlon Super League, which took place at Hamilton Island in Australia.
Triathlon: Super League
Coverage of stage five, which sees the riders take on a 182km journey from Valls to Lo Port.
Live Cycling: Tour of Catalunya
The crimes of Angus Robertson Sinclair, who raped and murdered Helen Scott and Christine Eadie and dumped their bodies six miles apart in East Lothian in October 1977. He became the first person in Scotland to be retried for the same crime after an acquittal, following a change in the double jeopardy law. He is suspected of murdering up to six other women.
Inside the Mind of a Serial Killer