"I can't be mistaken." Felix nodded a good morning to Kitty and, with an alert, quick stride crossed the sidewalk diagonally, and bent his steps toward Kling's.
The Englishman followed him with his gaze, his open pocketbook still in his hands.

"Is that gentleman a customer of yours ?" Had he seen a dead man suddenly come to life he could not have been more astounded.
"He is, and pays his rent like one." "Rent?
For what ?" The customer seemed completely at sea.
"For my up-stairs room.

He's my lodger and I never had a better." The Englishman caught his breath.

"Do you know who he is ?" he asked cautiously.
"Of course I do! Do you happen to know him ?" John had moved up now and stood listening.
"Not personally, but, unless I am very much mistaken, that is Sir Felix O'Day." "Ye ain't mistaken, you're dead right--all but the 'Sir.' That's somethin' new to me.

It's MR.