Powers of Darkness by Fred M. White

This news was worth running some risk for. Grenfell hugged himself as he stood listening in the cupboard. If Partridge meant anything, he was accusing Draycott of the murder of Gainsforth. This was an illuminating flash, but for a moment the light was too dazzling for Grenfell's mental vision. Why should Draycott have murdered Gainsforth, and what could he gain by the crime? How could he have done it when, by all accounts, he was in South America?

Hugh waited breathlessly for an indignant denial. He expected a violent outburst from Draycott. But nothing of the kind followed.