In the third book of this hilarious series—perfect for fans of Pizza and Taco—Pencil makes a new friend... and Eraser learns that three can be a crowd.Pencil and Eraser complement each other perfectly, like any best buds should. Who else could help Pencil when she messes up her drawings in art class? But what if she didn't make any mistakes? Enter Ruler, a new friend who can easily help Pencil keep her lines straight, without any need to ever erase again...When these school supplies learn a green crayon has gone missing, Pencil insists her new bud Ruler join their quest to save them. The two hit it off immediately, building off each other’s wacky ideas. And as the sole voice of reason, Eraser quickly starts to feel like the odd one out. With Stella and the rest of the students due back form lunch any minute, and each of their plans to rescue Green a bigger disaster than the last, can our dynamic duo learn to work as a trio before it’s too late?