Austin might guess that he was under suspicion as well as his son, but that did not matter so much.
Barrant instinctively realized that flight was impossible for Austin Turold, though he might seek to warn his son not to go near their London home because the police were after him.

But that was a warning which would be useless, for the police were ahead of him there.

Barrant reflected that he gained nothing by not divulging the object of his visit when the inference of it was so transparently palpable.

The disclosure might even serve a useful purpose by lessening Austin's apprehensions in his own case.

With this consideration in view he brought it out frankly-- "I wished to question your son about his movements on the night of the murder." "Is my son suspected--now ?" Barrant winced under the delicate inflection of irony which conveyed in that brief reply the inference of another blunder in his own changing suspicions.