The Norwegian connection illustrated a central challenge of the Gordievsky case, and a conundrum of spying in general: how to make use of high-grade intelligence without compromising its source. An agent deep inside the enemy camp may unmask spies in your own camp. But if you arrest and neutralize them all, then you alert the other side to the spy within their own camp, and you endanger your source. How could British intelligence take advantage of what Gordievsky was revealing without burning him?