The luster dims a bit for the author and illustrator of Night Workers (2000) and their other wonderfully soothing picture books, as they go more for poetry than science in trying to give younger children a sense of our planet's antiquity. While a dark-eyed boy picks up a rock on a beach, contemplates it quietly, then takes it home to place alongside his collection of sea glass, flashback scenes track his prize from its volcanic origins, as it "cooled in the shade of a thousand years," lay on a grassy highland while dinosaurs came and went, sheltered cave-dwellers, partly blocked an ancient city street, was washed down to the sea, and finally came to be "thrust" in some unexplained manner, "onto the beach." The semi-impressionistic paintings are tranquil as ever, even when that mood isn't really appropriate, and the rock, depicted as an indistinct, darkly orange blob, seems to move under its own power into and out of the calm ocean. Share this with a child at bed or rest time, but other rocks make less arbitrary, and more clearly articulated, journeys in such books as Meredith Hooper's Pebble in My Pocket (1996). (Picture book. 5-7)