In the shadow of King Arthur's Britain, love may be the kingdom's downfall . . . or salvation.

Former High Queen Isolde and Trystan, a mercenary with a lonely and troubled past, have undertaken a dangerous mission and endured a perilous journey to keep the traitorous Lord Marche from the throne of Britain. But now a new traitor lurks amongst the kings on Britain's High Council, and a new danger calls Trystan from Isolde's side and tests the strength of their secret marriage vow. Only Isolde knows that she is carrying Trystan's unborn child.

Marche and his Saxon ally Octa of Kent are massing their forces, and Britain's armies must prepare for final battle, in which they will either turn back the tide of the invaders or see their kingdom utterly destroyed. But when High King Madoc's young son is abducted by Octa's forces, Isolde must undertake yet another dangerous and daring mission, one that will bring her ever nearer to a secret that Trystan has kept for seven long years.

As the clouds of war gather, Isolde and Trystan must once again fight to protect Britain's throne. Together, they hold the key that can defeat Octa of Kent and Lord Marche. And yet the cost of Britain's sovereignty may be their forbidden love.