Sally and Nick are making shadow shapes when the batteries in their flashlight conk out. Luckily, the Cat knows where they can get some light: from his friend Shimmer, a firefly! But it turns out that Shimmer needs some help of her own: her friend Glimmer is in trouble. Fireflies call to each other using unique flashing light patterns, and Glimmer's pattern is all wrong. He needs help???fast! Can the Cat and Co. un-stick Glimmer from a giant spiderweb AND find enough light to put on a shadow show? You bet they can! With glow ink on every other spread and two sheets of glow stickers, this is a fun way to celebrate summer and to spark discussions on how different animals communicate!