They say he'd a motive for murdering Braden--and with them motive is everything.

It's the first thing they seem to think of; they first question they ask themselves.

'Why should this man have murdered that man ?'--do you see! 'What motive had he ?--that's the point.
And they think--these chaps like Mitchington and the London man--that Ransford certainly had a motive for getting rid of Braden when they met." "What was the motive ?" asked Mary.
"They've found out something--perhaps a good deal--about what happened between Braden and Ransford some years ago," replied Bryce.

"And their theory is--if you want to know the truth--that Ransford ran away with Braden's wife, and that Braden had been looking for him ever since." Bryce had kept his eyes on Mary's hands, and now at last he saw the girl's fingers tremble.

But her voice was steady enough when she spoke.
"Is that mere conjecture on their part, or is it based on any fact ?" she asked.
"I'm not in full knowledge of all their secrets," answered Bryce, "but I've heard enough to know that there's a basis of undeniable fact on which they're going.