Tavi is the true master of trickery and innocence--and doesn't for a moment believe that Innocent face.

Tavi leads him to Alec, then. "Fade, this is, ah, Troven. Troven, this is Fade. He'll help." Something about his tone implies 'He's safe.' Even with the touchy subject that Tavi doesn't know how to approach of who Fade actually is... there's just about no one he trusts above the man who helped raise him and who, with Bernard, substituted for his absent father.

(Septimus would approve.)