The Secret Knock Club is going green! Agnes and the other Secret Knock Club members are excited to be paired with kindergarten buddies, who need help learning to read. The younger kids are so adorable! Agnes dreams up a special "Weed and Read" project: They'll spruce up the neglected school courtyard and make it a new reading space. But will Agnes and her friends be able to round up enough helpers for the courtyard cleanup? And can they collect 1,050 milk cartons in time to make a recycled reading bench? Agnes has another problem: her kindergarten buddy Heather seems more interested in Agnes's fellow club member and former nemesis, Heather. It's double Heather trouble! But maybe Kindergarten Heather is planning something just for Agnes...As the deadline for the courtyard's opening ceremony draws closer, it looks like The Secret Knock Club might be heading for a disaster. Will Agnes and her friends pull it off?