River BBC1, 9pm
The troubled detective is convinced that Stevie’s investigation into the exploitation of illegal immigrants holds the key to her murder. Further questioning of someone close to the team reveals a system of immigration cases that could lead into some unexpected places. When a common link to certain businesses is found, it all starts to fall into place, but the link also leads to unfortunate repercussions. Crime drama, starring Stellan Skarsgard, Nicola Walker, Lesley Manville and Adeel Akhtar. Last in the series.