When the gnolls led us to face the traitor, Eustacio talk to Galluf mentally "add the traitor in our mental chat, so we can get stuff out of him without the other gnolls eavesdropping".

After the link is estabilished, Eustacio look the traitor and ask him mentally: "What you did to be disbanded? What is the identity of this Garret person? Tell me what you know and maybe we can plan something together"