I saw this television version of a Christie mystery story when it was shown back on Channel 5 in New York City in 1980. At the time I was surprised it was not shown on Channel 13, the Public Television Station that showed most of the Masterpiece Theater programs, but (aside from some Dorothy Sayers "Lord Peter Wimsey" stores, and THE MOONSTONE) the BBC productions rarely dealt with British detective stories. Another series, THE RIVALS OF SHERLOCK HOLMES had dealt with stories set in the Victorian and Edwardian period, so a period charm was involved in getting those stories onto Channel 13.<br /><br />The plot of WHY DIDN'T THEY ASK EVANS? dealt with a young couple stumbling upon a dying man who's only last words are the question of the title of the story (the novel was originally called WHY DIDN'T THEY ASK EVANS?, but subsequently was retitled THE BOOMERANG CLUE). The young couple start investigating the murder, and trace the crime to a set of people who surround a questionable doctor (Eric Porter). Despite the warnings of the father of the hero (John Gielgud), the hero (James Warwick) and the heroine (Francesca Annis) pursue their investigation - even as it gets murkier and more dangerous. The death of another suspect by suicide increases the apparent dangers as the killer starts looking into silencing the two amateur detectives.<br /><br />It's not a bad film, although I agree it was a bit too long for a single night's entertainment (if it had been done like later Miss Marple episodes with Joan Hickson, or the Hercule Poirot episodes, in two parts it would have been better). But it has it's strengths. One is the proper use of Porter as chief suspect, and a clever scene later in the film where he appears to be spying on the young couple who are investigating the mystery. If you stick to the film, you will be in for a fair surprise later on.<br /><br />But it has one failing. When dealing with a Christie novel the figures in the story have to be in a rigid schedule of movements so that the reader might be able to figure out what the secret of the plot is. I will only add that if you hear the dialog at one point, and how a little boy was almost killed (but wasn't), then you will find all the parts of the story coming together, and what the villain's motivations were.<br /><br />Except for that and the lengthy time the telefilm takes to tell it's story, it is quite a good film, and worthy as one of the best programs based on a Christie story in the period when their was a sudden renaissance in films based on her novels.