They walked long and rapidly down narrow lanes, then out among the vineyards, issuing at length into the Roman plain. In the distance the brick-built aqueduct of Servius Tullius was outlined against the sky. Juventinus turned round and said-- "Somebody is following us!" The two young girls turned round also. A flood of moonlight fell upon them, and the individual following them exclaimed cheerfully-- "Arsinoë! Myrrha!... And so I have found you again! Where are you going?" "We're going among the Christians," answered Arsinoë. "Come with us, Anatolius; you will see some curious things." "What do I hear? Among the Christians?--You have always been their enemy!" wondered the centurion. "With age, my friend, one grows better and more tolerant, or indifferent, if you like to call it so. This is a superstition neither better nor worse than other superstitions. And then one is capable of a good deal when bored. I am going among them for Myrrha's sake; it pleases her...." "Where is the church? We're out in the plain," murmured Anatolius. "The churches are destroyed or profaned by their fellow-Christians, the Arians, who believe in Christ otherwise than they do. You must have heard the debates about it at Court. So now the adversaries of the Arians are wont to pray in secret in subterranean vaults, as in the time of the first persecutions." Myrrha and Juventinus had lingered a little behind the others; Arsinoë and Anatolius could talk freely. "Who is he?" asked the centurion with a nod towards Juventinus. "The last scion of the ancient patrician family of the Furii," answered Arsinoë. "The mother wishes to make a consul of him. His only dream is to flee into some Thebaïd, or monkish community in the desert, to spend his days in prayer. He loves his mother and hides himself from her as from an enemy." "The descendants of the Furii, monks?... 'T is a queer age," sighed the Epicurean. They approached the _arenarium_, old excavations in crumbling tufa, and went down narrow steps to the bottom of the quarry. The volcanic blocks of red earth looked strange-hued in the moonlight. Juventinus took a little clay lamp from a dark niche, and lighted it; the long flame flickered feebly in its narrow gullet. They entered the darkness of the side galleries of the _arenarium_. Hollowed by the ancient Romans, the quarry was large and spacious and descended in steep slopes. It was therefore pierced by numerous galleries, for the use of workmen in transporting the tufa. Juventinus led his companions through the labyrinth and halted at last in front of a shaft from which he lifted the coverlid of wood; the party went cautiously down the damp and slippery steps; at the bottom was a narrow door; Juventinus knocked; the door opened, and a grey-headed monk introduced them into a passage hollowed in harder tufa. The walls on both sides from floor to vaulting were covered with slabs of marble, the seals of tombs in which coffins (_loculi_) were ranged.