The speaker looks back on a childhood game in which children led one another through yards, stairs, passageways and alleys, then stopped and asked, "where are you?" The poem suggests the players moved without relying on sight, guiding each other by touch and voice. Through this, they learned to build maps in their heads and to carry their own compass, "arrow and rose."
The feeling is warm, proud and a little wistful. The speaker compares the children to homing pigeons and says they were "so often right." The game even let them "slow time," which hints at how long and open a childhood afternoon can feel. Later, the speaker credits it for a lasting sense of direction, so strong that they can tell they are near the coast before smelling the salt air.
The repeated line about taking turns, and the phrase "a special trick of children," gives the ending a gentle, nostalgic ring. Something simple, done by children with nothing to do, turns out to have shaped them deeply.