Fand is the wife of Manannan Mac Lir (ruler of the Seas) and is a somewhat enigmatic goddess. Fand is a queen of the Sídhe said to live in a hidden palace that stands on a island in the middle of a lake. The story "The Sick Bed of Cú Chulainn" says of her:

"Fand is the daughter of Aed Abra; Aed means fire, and he is the fire of the eye: that is, of the eye's pupil: Fand moreover is the name of the tear that runs from the eye; it was on account of the clearness of her beauty that she was so named, for there is nothing else in the world except a tear to which her beauty could be likened."

Fand's beauty is said to be unforgettable. Cú Chulainn's charioteer spoke of her:

"Great is the beauty of Aed Abra's daughters,
Unfettered men before them conquered fall;
Fand's beauty stuns, like sound of rushing waters,
Before her splendour kings and queens seem small."

Althought the wife of Manannan, Fand falls deeply in love with Cú Chulainn. This love is doomed to be tragic, as Fand is immortal and Cú Chulainn mortal. Although Cú Chulainn is married to Emer he falls in love with Fand in return. Fand cannot, however, bring herself to doom Emer to lonliness. With a heavy heart Fand gives up Cú Chulainn resigning herself to sorrow for the rest of her days:

"Emer! noble lady!
Take your man to you:
Though my arms resign him,
And longing lives in me."

Manannan hears her lamentation from afar and appears on the scene with only Fand being able to see him. Manannan takes pity on her and shakes his cloak between Fand and Cú Chulainn. This has the magical effect of making both Fand and Cú Chulainn forget each other forever and ensures that there paths will never cross again.

Fand understands the pains and passions of the heart, and can give gifts and insights on matters of lost love. Remote islands in the midst of lakes are places where she can be interacted with and prayed to.

The Following is a poem by Nuala Ní Chonchúir and is a great emotional glimpse into this tale:

Émer wakes to the gabbling
of lake birds, pushing
her arms over her head
until her breasts are taut,
and her calves ache
with the stretch of flesh;
with a sigh she stands
to size up the day, and
seize it, before it passes.

They thought that one drink
would cause me to forget,
but I poured it away
before it reached my lips.
I still keep the whetstone
that sharpened the knives
that would have cut the
life from Fand, but she learned
to leave what wasn't hers
to whom it really belonged.

Fand reaches for her man
to stroke his downy back,
but finds an emptiness to
match the gap in the Mournes,
and a jolt of memory
that shakes her awake.
Fand, the pure and covetous,
she is the pearl of beauty,
the tear that covers the eye.

You wasted for a year
when the green-cloaked hag
said I wanted to lie with you;
long lying made you sick but
you came to me anyway,
the lusty hound who replaced
my love, but your wife knew
what is fresh grows stale,
so I let you go, and escaped
a death at her jealous hand.