When Coach's whistle goes missing and the football team can't practise, Ollie and his new friend, Aria, lead the search. There are clues about where the whistle might be and who took it - missing shoelaces, a dropped leaf and twig, some mud and a chewed net. It takes a while for the rest of the team to follow Ollie, who's got great detective skills, as they find him hard to understand because of his cleft. But Aria's used to identifying bird calls, and she encourages their teammates to really listen. Together, they learn about each other's strengths, teamwork and acceptance, and they find the whistle in a surprising place.