Witness Before the Fact

One of the very last authors of detective fiction from the genre's "Golden Age" INDEPENDENTSuicide or murder? Despite all indications to the contrary, Alec Methven had not eaten his last meal in solitude, and somebody was very anxious to conceal that fact. As if one death on the beautiful island of Madeira was not enough, there was another. Peter Corey, who had found Methven's body, had a cast-iron alibi: he was on a plane to the island at the time of the death, en route to visit his old friend.
But what of the second killing that so inexplicably occurred?