A quiet coastal town is invaded by a military force from the south; a mixture of mature, battle-hardened soldiers and young conscripts. Led by the cruel Commander Savage and his inner guard, they are the elite troops of the Wendon Militia: ruthless in their determination to achieve their objectives and merciless when shown the slightest resistance. This is the story of Alice Seamarsh, adopted by the Seamarsh family as a foundling after the Great Death and now a teenager, growing up in the town of Goodfleet. Alice's life is turned upside down when a young soldier called Neil, little more than a boy, is billeted on the Seamarsh family. The two youngsters become friends, but there is rivalry for Alice's affections. Rob, Alice's step-brother, makes it plain that he is unprepared to stand idly by and see an enemy soldier steal away someone he believes he loves.Then, when it looks as if the invaders will triumph, Jack Newman, the Mereman, an ex-soldier and a man of the marshes who has hidden himself away for many years, appears on the scene. Can Newman galvanize the terrified community into challenging the seemingly invincible occupying force?When there seems to be no alternative to perpetual oppression and probable death, the entire Seamarsh family - Alice, Terry, Adam and Rob - step forward and are woven willingly into the Mereman's plans, to become pivotal in the daring gamble that becomes the story's shocking climax.