The incident is from the Love Stories of Parthenius, who
preserved fragments of a lost epic on the expedition of
Achilles against Lesbos, an island allied with Troy.

The daughter of the Lesbian king
Within her bower she watched the war,
Far off she heard the arrows ring,
The smitten harness ring afar;
And, fighting from the foremost car,
Saw one that smote where all must flee;
More fair than the Immortals are
He seemed to fair Pisidice!

She saw, she loved him, and her heart
Before Achilles, Peleus' son,
Threw all its guarded gates apart,
A maiden fortress lightly won!
And, ere that day of fight was done,
No more of land or faith recked she,
But joyed in her new life begun,-
Her life of love, Pisidice!

She took a gift into her hand,
As one that had a boon to crave;
She stole across the ruined land
Where lay the dead without a grave,
And to Achilles' hand she gave
Her gift, the secret postern's key.
“To-morrow let me be thy slave!”
Moaned to her love Pisidice.

Ere dawn the Argives' clarion call
Rang down Methymna's burning street;
They slew the sleeping warriors all,
They drove the women to the fleet,
Save one, that to Achilles' feet
Clung, but, in sudden wrath, cried he:
“For her no doom but death is meet,”
And there men stoned Pisidice.

In havens of that haunted coast,
Amid the myrtles of the shore,
The moon sees many a maiden ghost
Love's outcast now and evermore.
The silence hears the shades deplore
Their hour of dear-bought love; but THEE
The waves lull, 'neath thine olives hoar,
To dreamless rest, Pisidice!