A 40 year old mystery is stirred, and a new danger rises to the surface

1940:

Anglo-Irish spy, Michael McBride, uncovers a secret that could cost him his life when he finds a hidden stash of Nazi submarines in Guernsey. With German agents suddenly appearing in Ireland, Nazi relations with Irish Republicans become apparent, and McBride suspects an invasion may be imminent.

1980:

Forty years on, the war is long over, and the German submarine mystery is a secret that remains untouched. However, when McBride's son, a bestselling American author, starts to dig into his father's history, valuable details of the Irish invasion codenamed Emerald Necklace come to light, risking the lives of everyone involved.

One secret, two stories, and forty years between them, Emerald Decision is a gripping political thriller, perfect for fans of Tom Clancy and Brad Thor.