Higgins was the principle liason for two handlers who ran five operatives in East Berlin during the Cold War. The problem was, there was a leak, but the head office didn't know where! The records of all five operatives was squeaky clean. All were routinely spied upon to ensure their realities matched their reports. Only one of the operatives, Grace, had access to the West. The handlers (and Grace) were periodically cycled through refresher training, which including top of the line lie detector tests, some under hypnosis. The operatives weren't supposed to know one another, but because of a chance meeting between Grace, Tom (one of the handlers), and Charlie (another operative), Grace knew Charlie was another operative, but Charlie didn't know Grace was part of the team. Two of the operatives, Dan and Linda, were married, so both knew the other one was an operative, and they worked well together. Of the operatives, George was the odd man out, not really fitting the mold. As such, he was the only one who had regular contact with both Tom and John (the other handler). Of the rest, only Dan was aware that another handler was working with Tom to manage their team of an unknown size. Summary: Liaison: Higgins Handlers: Tom John Operatives: Grace Charlie Dan Linda George Where was the leak?