The prince recognized the voice of Bischofswerder, and smiled, but he knew not that it was permitted him to hear it to inspire him with courage.
“Well, so let it be; the fathers shall see that I am a believer,” cried the prince.
Immediately one of the brothers put his own cloak, three-cornered hat, and mask upon his highness, still remaining cloaked and masked himself, much to the astonishment of the passive prince. “Come, now, the Invisibles await you,” said one of the masked. The prince stepped courageously into the little corridor which led to the secret stairway, one brother preceding him, causing a soft light to illumine their path, the other following him.
In silence they reached the side-door of the palace, where a close carriage awaited them.
“Where are you taking me?” asked Frederick William, as he entered, followed by the two brothers.
“To the Invisibles,” answered a strange voice.
Again the prince essayed to begin a conversation, his only response being, “Purify your heart and pray.” Silently they galloped over paved and unpaved streets, the prince heartily repenting having been drawn into this adventure. He thought of his charming and beloved Wilhelmine, and half determined to give the command to drive to Charlottenburg. The fact of Bischofswerder being with him, and fearful of appearing weak and wanting in courage in the eyes of his friend and favorite, prevented him.
After several hours’ drive, they stopped at the marble palace of Potsdam, near the one which the prince was accustomed to occupy. His highness looked cautiously around, and breathed more freely, as he felt that he was now surely among friends.
The white palace stood silent and deserted in the darkness, this palace at Potsdam being only used for the guests of the king. The carriage stopped at the side-door, where there was no sentinel, and they alighted, entering the palace, winding along the corridors in the same order as before, guided by the glimmering light of the one preceding. Solemn music, strange ringing sounds, fell upon the ear as they advanced. Sometimes they were sharp and cutting as glass, then threatening and penetrating as the wind, shrieking and moaning, causing one to be very nervous if not terrified.
The farther they proceeded the louder grew the sounds, and at intervals groans, moans and wailings were heard, as of those waiting and imploring for mercy.