They are touched throughout with a woman's thought and feeling, inflamed by the poetic genius with which Browning has endowed her.

Balaustion is his deliberate picture of genius the great miracle.
The story of the _Alkestis_ begins before the play.

Apollo, in his exile, having served King Admetos as shepherd, conceives a friendship for the king, helps him to his marriage, and knowing that he is doomed to die in early life, descends to hell and begs the Fates to give him longer life.

That is a motive, holding in it strange thoughts of life and death and fate, which pleased Browning, and he treats it separately, and with sardonic humour, in the Prologue to one of his later volumes.
The Fates refuse to lengthen Admetos' life, unless some one love him well enough to die for him.

They must have their due at the allotted time.
The play opens when that time arrives.