Tadhg MacNaill is a harper, a bard in the court of Conn Sleaghear, king of the Cruthini in 6th-century Ireland. His wife, Maire ni Donnall, is a midwife and healer. Their life together is good by the standards of the day; although they have not been blessed with a child, both are productive, well-respected members of their society, and they are happy. But then, one Bealtaine night, Tadhg dares to listen to unearthly music emanating from a faerie mound, and by morning his form is worn by a changeling; he himself has been taken to a Sidhe palace under Lough Neagh, where he plays nightly for the court and acts as consort to the faerie queen.

He cannot leave. Nor does he desire to.

But Maire isn't content to live with the changeling, nor will she simply leave him and seek a new life. Acting on the counsel of a magical trout in a holy pool by the lough, she dives into the deep and murky waters and enters the Sidhe palace. She finds her husband but cannot free him, so she drinks the faerie wine and is also bound to remain.

Time passes in a dream for the pair, who rarely interact. Tadhg performs nightly for the court (and, in a different capacity, for the queen); Maire has little to do besides dally with the faerie king. Meanwhile, in the mortal world above them, time passes quickly. Some 1,400 years have flown by.

Eventually, strife in the world above brings an end to the Sidhe, and as they pass from existence, they free the captive pair. As a final gift before vanishing, the king and queen grant Tadhg and Maire the powers of sight, speech and invisibility, so they can understand what they see in a very different world, speak and understand modern languages and, as needed, hide from view. They emerge from Lough Neagh in what appears to be the late 1970s, but they are separated; Maire is rescued from the water by a lone fisherman and taken to Belfast, while Tadhg is picked up by a passing motorist. Although he is also taken to Belfast, he meets and befriends a trio of traveling musicians. Tadhg, who still has the harp he made in his youth, quickly finds a place among them and goes south with them to Dundalk.

But this is the time of the Troubles, and Tadhg and Maire both find themselves involved in violence they can barely comprehend. Each believes the other dead, and each ends up on opposite sides of the struggle. And each is possessed by a powerful spirit -- he by the Horned God of winter, she by the healing Goddess of summer. And a mighty conflict is coming between them on Samhain.

Given the buildup -- which involves the IRA, selkies, smuggled American weapons, and raising a vast army of warriors from ages past, including Brian Boru and Maeve, as well as the very spirit of Mother Ireland -- the climax at the fabled Hill of Tara is ... well, a bit anticlimactic. The story, which has been deeply impactful throughout the novel, sort of sputters to an end.

I first read this novel by Mildred Downey Broxon sometime in the 1980s, inspired to seek her out after reading The Demon of Scattery, a novel she cowrote with Poul Anderson. While Too Long a Sacrifice doesn't stand quite as well on its own, it is still a satisfying book, with rich characters and a deep understanding of the forces that drove the violence in Ireland. Despite it's abrupt ending, I'm glad I found Too Long a Sacrifice again.