It was seen but for an instant.

No sooner did it disappear, than all was once more quiet and obscure.

Profound Darkness again surrounded him, and the silence of night was only broken by the whirring Bat, as She flitted slowly by him.
With every instant Ambrosio's amazement increased.

Another hour elapsed, after which the same light again appeared and was lost again as suddenly.

It was accompanied by a strain of sweet but solemn Music, which as it stole through the Vaults below, inspired the Monk with mingled delight and terror.