He was waiting for the day when he and his Straw Hat Master would meet on a narrow road and face each other. Before that, all they had to do was to follow their own choices and go on without regrets.
This may require a little patience, but more of the courage to just look ahead without hesitation. He is not in a hurry.
Trafalgar Law leaned against the door frame and looked at Straw Hat Luffy's back as he ran out of sight with a carefree bark. He lowered his head and touched his knuckles with his lips, "Long live the king."