He fell to wondering one day if that, too, had anything to do with Arkwright.

He determined then to find out.
Shamelessly--for the good of the cause--he set a trap for Billy's unwary feet.
Very adroitly one day he led the talk straight to Arkwright; then he asked abruptly: "Where is the chap, I wonder! Why, he hasn't shown up once since the operetta, has he ?" Billy, always truthful,--and just now always embarrassed when Arkwright's name was mentioned,--walked straight into the trap.
"Oh, yes; well, he was here once--the day after the operetta.

I haven't seen him since." Bertram answered a light something, but his face grew a little white.
Now that the trap had been sprung and the victim caught, he almost wished that he had not set any trap at all.
He knew now it was true.

Arkwright had been with Billy the day after the operetta, and her tears and her distress that evening had been caused by something Arkwright had said.

It was Arkwright's secret that she could not tell.