The Flight of Diarmuid and Gráinne

She looks across the feast hall at the man she is about to marry and thinks: no.

Fionn Mac Cumhaill is old — not old by mortal reckoning, exactly, but old in the way that great captains go old: worn in the face, deliberate in the hands, the fire of the man still burning but lower, banked. Gráinne is the High King’s daughter and she has been married once already and she knows what she wants, which is emphatically not this.

She looks down the table instead to Diarmuid Ua Duibhne.

Diarmuid is Fionn’s best warrior and his foster-son, raised by the love-god Aonghus Óg, and he carries on his forehead a love-spot — a mark placed there by a supernatural woman when he was a young man, which causes any woman who sees it to fall immediately and irrevocably in love with him. He keeps it hidden under his hair and his hood. But the hall is warm and his hood is down, and Gráinne sees the spot.

She passes him a drugged cup first — she drugs everyone else at the table to make sure they sleep — and then she comes to him directly: “I put you under a geis, Diarmuid Ua Duibhne, to take me out of this hall tonight before Fionn Mac Cumhaill wakes.”

A geis is a sacred compulsion, impossible to refuse without spiritual destruction. Diarmuid is bound.

He wakes his companions to witness that this is not his choice, that he is under compulsion, that he knows exactly how this ends. They hear him. They cannot help him. He takes Gráinne out of Tara.

The pursuit begins.

For sixteen years Fionn hunts them across Ireland with all the resources of the Fianna — which is to say, with all the resources of a man who has more woodcraft, more patience, and more sources of intelligence than any other hunter in the island. Diarmuid and Gráinne sleep in a different place every night. The standing stones and dolmens scattered across Ireland — the leaba Dhiarmada is Ghráinne, Diarmuid and Gráinne’s bed — are all places where they slept one night and moved before morning.

The god Aonghus Óg, Diarmuid’s foster-father, helps when he can: carrying Gráinne away under his cloak when the Fianna closes in, appearing at critical moments with warnings. But Aonghus cannot fight Fionn directly. He can only buy time.

What changes in sixteen years is everything. The geis that drove Diarmuid out of Tara becomes, by the third year, something else — a genuine devotion that neither of them had anticipated. Gráinne’s initial compulsion softens into love. Diarmuid’s reluctant loyalty to a sworn obligation becomes, impossibly, the center of his life. They have a son. They have a home, for stretches. They have, against all probability, something that looks like happiness.

Fionn eventually offers peace. He is old and tired and perhaps, in the way of old men, he has decided that the pursuit is costing him more than the prize is worth. He offers reconciliation. He offers to let them return to the Fianna and live in peace.

They accept. Diarmuid and Gráinne return to the world.

The reconciliation lasts until a boar-hunt on Benbulben. Fionn organizes a hunt on the mountain where a magical boar lives — the same boar that is Diarmuid’s fatal geis, his one specific vulnerability, the thing that will kill him. He may not have known this. He may have known exactly. The sources leave the question open, which is the worst answer.

The boar kills Diarmuid on the mountain. Fionn stands over him with the healing water in his cupped hands that could save Diarmuid’s life, and twice he lets the water run through his fingers before he tries to save him, and the third time he tries it is too late. The sources leave that open too.

Gráinne curses Fionn from the mountain.

Later — years later — she marries him anyway. The sources say this and offer no explanation, and the absence of explanation is the most devastating thing in the story: the woman who flew across Ireland for love of one man sitting in the hall of the man who let him die, and the long silence after.