"Doctor Hilary was over here again yesterday. He enquired after you, and asked to be very kindly remembered to you. I should like Doctor Hilary to attend me in any illness. He gives one such a feeling of strength and reliance. There's absolutely no humbug about him.
"Much love, my dear Trix, "Yours affectionately, "Pia Di Donatello."
Trix read the letter through very carefully, and then dropped it on her lap.
"It wasn't Doctor Hilary!" she ejaculated. "So who on earth was it?"
She sat gazing through the opening of the summer-house towards the garden. It was the oddest _puzzle_ she had ever encountered. Who on earth could it have been? And why--since it wasn't Doctor Hilary--had Pia jumped to the conclusion that she--Trix--knew who it was?
It wasn't Mr. Danver, that was very certain. "Social inferior" put that fact out of the question. But then, what social inferior had been mixed up in the business? Or--Trix's brain leapt from point to point--had Pia's trouble nothing whatever to do with the mad business at the Hall? Had she and Pia simply been playing a quite amazing game of cross-purposes that evening? It would seem that must have been the case. Yet the recognition of that fact didn't bring her in the smallest degree nearer the solution of the riddle. Again, who on earth was it? What social inferior was there, could there possibly be, at Woodleigh, to cause Pia a moment's trouble? Every preconceived notion on Trix's part, including the colour of the soap-bubble, vanished into thin air, and left her contemplating an inexplicable mystery.
Whatever it was, it had affected Pia pretty deeply. It was absurd for her to say the incident was closed. Externally it might be, in the matter of not referring to it again. Interiorly it had left a wound, and one which was very far from being easily healed, to judge by Pia's letter. It had not been written by Pia at all, but by a very bitter woman, who had merely a superficial likeness to Pia. That fact, and that fact alone, caused Trix to imagine that she had been right when she told Tibby--if not in so many words, at least virtually speaking--that love had come into Pia's life. Love embittered alone could have inflicted the wound she felt Pia to be enduring. And yet the wording of her letter would appear to put that surmise out of the question. Truly it was an insolvable riddle.