Counting down from ten to one, a girl and a boy empty the night sky of fireflies as - counting up from one to ten - they fill their jar with them. But once captured, the fireflies' light flickers and fades, so in a generous good-night gesture, the children release them. Luminous pictures and a chant-aloud text combine to make this two-way counting book as joyous and magical as catching fireflies on a summer night.