It took Sparrow whole one hour to get back to where he and the others separated ways, he knew that they had left the place long ago but knowing his master, he must have left him a clue where to look for them, so he searched the whole street and found a small marking on the wall, it was not that conspicuous but his master must have put into consideration his Hawk Eyesight gift when he placed the markings.
So discreetly marked that it resembled a mere doodle, ensuring that only those with a keen eye, like Sparrow, would discern its significance.