Three American army deserters claim refugee status in Canada, and ICS must deal with the personal and political fallout.

A deadly assassin shows up in Toronto, drawing ICS into a web of international political intrigue.

MI6 horns in on the ICS investigation of tainted heroin and an African drug smuggling ring.

The Prime Minister of Quebec feels threatened and ICS follows the trail of a former FLQ bomber to a small town straddling the Canadian/US border.

An eco-terrorist sabotages an Alberta pumping station and Gray and Layla must untangle an international corporate espionage scheme.

Counterfeit pharmaceuticals kill an American rock star. ICS searches for the Canadian link but Bianca LaGarda takes matters into her own hands.

While tracking a fundamentalist Christian sect moving "child brides" across the border, Gray meets his match.

Maggie becomes personally invested in the plight of two young Filipino children, victims of a human trafficking scheme.

Kessler suspects the Canadian military is complicit in the cover-up of a scheme to smuggling cheap Afghan heroin into the country.

The frozen body of a Russian man is found in a railway car triggers an ICS investigating of the smuggling of blood diamonds via the Canadian north.

ICS face escalating gang violence when a U.K. Tamil gang member enters the country for his son's life-saving surgery.

As international leaders debate Arctic sovereignty, Kessler and ICS fight to rescue a Canadian submarine crew trapped under the polar ice.

ICS discovers that toxic sludge is being trucked across the border and dumped in the Canadian wilderness. They follow a trail to a vicious criminal gang, who gain control over Gray and his father. As Gray struggles to save his father, he sets off a chain of events which bring about the season's shocking conclusion.