Louis Aston Knight Sunny Afternoon on the Canal painting

Louis Aston Knight Sunny Afternoon on the Canal painting
Peter Paul Rubens Samson and Delilah painting
"That's what I want to ascertain. You know, I suppose, that unless the matter is cleared up, Mrs. Barclay, who is an old friend of yours, will in all probability be tried for murder."
The man gave a violent start.
"I don't know who you are," he cried, "nor how you come to know what you do know, but will you swear that this is true that you tell me?"
"Why, they are only waiting for her to come to her senses to arrest her."
"My God! Are you in the police yourself?" "No."
"What business is it of yours, then?"
"It's every man's business to see justice done."
"You can take my word that she is innocent."
"Then you are guilty."
"No, I am not."
Who killed Colonel James Barclay, then?"