He knew his mother's birds; and thus he prayed:
"Be you my guides, with your auspicious aid,
And lead my footsteps, till the branch be found,
Whose glittering shadow gilds the sacred ground."
DRYDEN, _AEneid_, BOOK VI.

The branch was soon found, for the doves, fluttering away, yet keeping
within view of AEneas, presently perched upon a tree, and from out the
foliage of this tree, as the Trojan chief approached it, there flashed
upon his eyes the gleam of the golden bough. Eagerly he plucked off
the branch, and gladly bore it to the cave of the Sibyl.

They now set out on their perilous journey. At the mouth of the gloomy
cavern by the side of Lake Avernus, which was the opening to the road
that led to Hades--the kingdom of the dead--they offered sacrifices to
the gods. Then they plunged into the cave, the Sibyl going first, and
AEneas following with sword drawn, as his guide had directed. Many
strange and terrible sights they saw on the way.

Full in the midst an aged elm
Broods darkly o'er the shadowy realm;
There dream-land phantoms rest the wing,
Men say, and 'neath its foliage cling,
And many monstrous shapes beside.
There Centaurs, Scyllas, fish and maid,
There Briareus' hundred-handed shade.
CONINGTON, _AEneid_, BOOK VI.

AEneas was about to rush on these monsters with his sword, when the
Sibyl informed him that they were no real beings but merely phantoms.