Why didn't they ask Evans?

Agatha Christie is the most widely published author of all time and in any language. Now Collins has adapted her famous detective novels for English language learners. These carefully adapted versions are shorter with the language targeted at upper-intermediate learners (CEF level B2). Each reader includes: A CD with a reading of the adapted story; Helpful notes on characters; Cultural and historical notes relevant to the plot; A glossary of the more difficult words. Bobby Jones is playing golf - terribly. As his ball disappears over the edge of a cliff, he hears a cry. The ball is lost, but on the rocks below he finds a dying man. With his final breath the man opens his eyes and says, ‘Why didn’t they ask Evans?’ Bobby and his adventure-seeking companion Frankie set out to solve the mystery of the dying man’s last words only to find their own lives in terrible danger.