It thrilled the girl sitting in the shade--partly with fear.

In three weeks or so, the speaker would be back in the full inferno of the front, and because of her father's behaviour she would probably not be able to see him in the interval.

Perhaps she might never see him again.
Perhaps this was the last time.

And he would go away without giving her a thought.

Whereas, if she had played her cards differently, this one last day, he might at least have asked her to write to him.
Many men did--even with girls they hardly knew at all.
Just then she noticed a movement of Beryl's, and saw her friend's small bare hand creep out and slip itself into Aubrey Mannering's, as he sat beside her on the grass.