“But no one can enter it!” Maggie exclaimed.  “The place is like a fort.  No stranger may pass the threshold even.  The Prince has told me himself that he receives no visitors.”

La Belle Nita smiled.  From a pocket somewhere within the folds of her flowing gown, she produced two small keys.

“Listen,” she said.  “The house in Curzon Street has been called the House of Silence.  There are many servants there, but they come only from beneath and when they are summoned.  There is what no other person has ever possessed—­the key of the front door.  There is also the key of the cabinet.  Prince Shan has ordered his automobile for two o’clock.  It is now barely midnight.”

The keys lay in the palm of Maggie’s hand.  Her heart had begun to beat quickly.  Somehow or other, she was conscious of a thrill of excitement which she had never before experienced, even when she had sat back in her corner of the railway carriage, watching for the frontier, knowing that the wires were busy with her name, and that men who knew no mercy were on her track.

“If the servants should hear me?” she faltered.

“You say only ’I await the Prince’,” La Belle Nita murmured.  “That key never leaves his own person save for one in great favour.  They will believe that he gave it to you.  You will be unmolested.”

A queer sensation suddenly assailed Maggie.  She felt extraordinarily primitive, ridiculously feminine.  She looked at the girl opposite to her, the girl whose body was draped in perfumed silks, whose face was thick with rice powder, whose eyes were sad.  She felt no pity.  What feeling she had, she did not care to analyse.

“Is this your key?” she asked.

“It was mine once, but its use has been forbidden to me,” the girl replied.  “Prince Shan is a changed man.  Something has come into his life of which I know nothing, but as it has come, so must I go.  I give you your chance, lady, but already I weaken.  Go quickly, if you go at all.  Please leave me, for I am very unhappy.”

Maggie stole quietly out and made her way through the jostling throng back to her own box, which for the moment was empty.  She slipped on her cloak, and from the hidden spaces where she stood she looked across the auditorium.  The silent figure in green silk robes was still seated in his place, his eyes following the movements of the dancers, his head a little thrown back, a slight weariness in his face.  He was still alone.  He still had the air of being alone because it was his desire.  Once he looked up towards the box in which she was, and Maggie, although she knew she was invisible, shrank back against the wall.  She set her teeth hard and looked back through the slightly misty space.  An unfamiliar feeling for a moment almost choked her.  She waited until she had vanquished it, then adjusted her mask and left the box.

CHAPTER XX