Summer vacation turns into an adventure for the three Nicholl sisters when Mr. Gilbert Chesterton and his wife come to town. Eleven-year-old Clare hopes to write a detective story. Eight-year-old Cece wants to be a champion roller-skater. And ten-year-old Joan just wants to learn how to play the locked piano in the family living room. But as they befriend the Chestertons, skating accidents, surprising friendships, puppet shows, and mystery solving ensue!