All aboard the train-car pool! A new lineup of students is off and rolling to Choo-Choo School. After reciting their classroom rules—work hard, play fair, be kind—it's time for some math to get the wheels turning. Then everyone's ready to climb a hill in gym (it's good to blow off steam), sing songs in music (Flat Car is a bit off-key), and learn the whole alphabet, especially the letter R. In one of Amy Krouse Rosenthal's last works, lighthearted verse portrays a world where train stations are classrooms, the conductor doubles as the teacher, and Boxcar is happy to hand out tissues to anyone who ah-choo-choos.