Sloane called Poole one day after the Alliance proposed to have a vote on whether or not to kill Alexander Khasinau. Sloane told Poole that the vote was split, and he needed Poole to back him up with aggressive action. He told him, however, that two Alliance members (Oscar Dunst and Jean Briault) were still indecisive about the vote.
Later on, Poole showed up at SD-6 with vital information. He told him that Briault was working with Khasinau by showing him false bank account transactions. Despite the information, Sloane didn't believe that Briault was a traitor, and Poole left. Later that night, Sloane had a change of heart and decided that Briault needed to be taken out. Sloane traveled to Montreal and assasinated Jean Briault. Later on when the voting took place in London, the motion to declare war on Khasinau's organization failed. Sloane quickly figured out that Poole was really working for Khasinau, but he denied it when Sloane accused him. Shortly after, he's seen entering his limo, with Khasinau inside.
Poole was briefly mentioned again in Rendezvous, during an Alliance of Twelve discussion on the course of action for dealing with Khasinau. Ramon Velosa mentioned that Poole confessed that he was working for Khasinau "under duress," and the Alliance subsequently agreed to declare war. Although it wasn't confirmed, Poole was not mentioned again after the meeting, so it's highly likely that the Alliance tortured and executed him.