The Butler seemed to know which side his bread was buttered back in the Embryo Room of Once Upon A Time, 'He thinks you're the boss!' No.2 barks at No.6, after they've changed places. No.1's the boss' No.6 responds.
And then in the cavern of Fall Out, the Butler stands at the side of his new master. 'And you my little friend' No.2 greets his one time manservant, 'Ever faithful, come on, come on' he beckons. But the Butler remains steadfast. 'New allegiances' says No.2 'such is the price of fame and failure. Dear me, how sad.'
So the Butler was no fool. He could see what was happening, how the game was panning out. His former master, a spent force, a beaten and failed man, who is now about to be put on trial. while Sir is now famous, a better man to ally himself with, and without question. As the Butler accepts the Prisoner just as the Prisoner accepts the Butler. More than this, the Butler assists his new master in active revolt against the system of the Village, what's more they escape together, all the way back to London. As the Prisoner drives off in his Lotus Seven to eventually hand in his letter of resignation, the front door opens with a very familer electronic hum, and as the Butler enters 1 Buckingham Place, the door closes automatically behind him.
So what is the Buter doing inside No.,1 Buckingham Place? Well obviously he's busy packing two suitcases for his master, in preparation for his departure, to the Village of course! Such is the price of fame and failure, that even new alliances last no longer than they are necessary!
Be seeing you