When Canadian Prime Minister Justin Trudeau stood up and accused India of being behind the killing of a Sikh activist on Canadian soil last year, the world took notice. South Asia correspondent Avani Dias travels to Punjab where tensions are high and the authorities are watching. This is the Sikh homeland where a banned separatist movement is fighting to create its own independent nation of Khalistan. Avani visits the family home of the man murdered in Canada, Hardeep Singh Nijjar, and learns of unusual activity in the lead up to his killing.