The tide between us / Olive Collins.

Enhanced descriptions from Syndetics:

1821: After the landlord of Lugdale Estate in Kerry is assassinated, young Art O'Neill's innocent father is hanged and Art is deported to the cane fields of Jamaica as an indentured servant. On Mangrove Plantation he gradually acclimatises to the exotic country and unfamiliar customs of the African slaves, and achieves a kind of contentment. When the new heirs to the plantation arrive from Ireland they resurrect the ghosts of brutal injustices against Art. He bides his time and hides his abhorrence from his owners. During those years he prospers, he sees his coloured children freed after emancipation, he owns land and his family thrive. Eventually he is promised seven gold coins when he finishes his service, but he doubts his master will part with the coins. One hundred years later in Ireland, a skeleton is discovered beneath a fallen tree on the grounds of Lugdale Estate. By its side is a gold coin minted in 1870. Yseult, the owner of the estate, watches as events unfold, fearful of the long-buried truths that may emerge about her family's past and its links to the slave trade. As the skeleton gives up its secrets, Yseult realises she too can no longer hide.