Grover and Avigail join their friends Brosh and Mahboub to clean up a playground in Israel as a mitzvah, and although grouchy Moishe refuses to participate, he finds his own way to make the world a better place.
In Israel, while Brosh is preparing to celebrate Rosh Hashanah, his favorite cap goes missing and he fears Grover or another of his friends has taken it.
"Grover takes a trip to Israel to visit Brosh and Avigail. While he's there, he writes emails to his friends on Sesame Street telling them about the many things he sees and does while on his trip"--