Cat among the pigeons

Late one night, two teachers investigate a mysterious light in the school Sports Pavilion. Among the tennis racquets and lacrosse sticks, they find the body of the unpopular games mistress - shot through the heart. Schoolgirl Julia Upjohn knows too much, and begins to worry that she might be the next victim. Can detective Hercule Poirot find the killer before the 'cat' strikes again?