Hannah and Abba--Hebrew for "Dad"--are spending time together in nature on Tu B'Shevat, the Jewish Arbor Day. As Abba rests under a carob tree, Hannah declares that she wants to climb a tree. The carob tree's trunk is too skinny, but can she climb a eucalyptus tree or a pine tree or an olive tree? When each poses a challenge--for being too scratchy, for not having footholds--Abba offers new inspiration for climbing and insight into what Hannah and the carob tree share in common.