When she discovers that her husband has been unfaithful, Niamh O'Sullivan decides that life is no longer worth living.
She casts herself into the clear blue waters of Kinnagoe Bay and expects it to be the end.
Instead she's rescued by merman Adam Spellman and taken to MerLand, an undersea kingdom more beautiful than any she could have imagined.
Within a year she's borne him a pair of beautiful twins and been loved more than she's ever been loved before.
The only problem is that she's wracked with guilt at the thought of the pain she caused her loved ones by leaving them so abruptly and without a word of explanation.
Adam has the power to facilitate a trip back to Earth, but it means that Niamh has to leave him and her children behind.
Can she take the chance of losing all she holds dear just to lay the ghosts of her past to rest, even if closure would give her the chance of perfect contentment?