Silent Witness

Leo receives devastating news from home; Nikki goes to the river, where two unidentified female bodies have surfaced.

Erin rescues Leo; police raid the unit and find the body of Armstrong, the man linking the investigations in London and Sheffield.

The team is called to a drive-by shooting outside a London nightclub.

Leo, Harry and Nikki search for an explanation of the shootings; the team searches for the gunsmith before he can supply the gangs with more weapons.

Harry must investigate the death of a woman who seems to have drowned in a pool containing three inches of water.

Nikki and Leo follow the trail of the philosophical serial killer; Nikki's beliefs are put to the test; Harry uncovers the truth about the drowning victim.

Nikki goes to the site of a suicide, but it becomes apparent that someone is on a killing spree on the streets of London.

Nikki and Harry realize that the source of the faked medication is a wholesaler who is watering down the drugs to increase his profit.