The world of counter terrorism is a dirty business. Intelligence services and law enforcement need to infiltrate terrorist cells to see what they are planning and part of those efforts involve the recruitment and running of human sources/agents. What are these sources able to do to help the good guys defeat the bad guys? In the wake of allegations that Canada's spy agency CSIS used a human source to 'traffick' UK 'schoolgirls' into ISIS from Turkey a much needed overview of how human sources are deployed should help shed some light on this practice. Borealis has an in-depth conversation with Al Treddenick, former CSIS officer, and Mubin Shaikh, former CSIS human source.