Last Hope of Eden follows twin teenagers who can summon a Mighty Angel who helps them in dire times of need. Zak and Sarah learn about "their" angel through near tragedies when they're five and ten years old. They serve in the mission field with their parents in Africa, endure bullies at school, grow in their faith through adolescence, attend high school in Edinburg, Scotland and visit their Uncle Joe, Aunt Mary, and cousins Airo, Run, Shy and Ruby annually on the island of Eden in the North Sea.
When they're sixteen they're asked to go on a mission to rescue their cousins who've been taken from King's Forest by shadow-demons and forced into a vortex that took them to the Remnant Forest, a forest within a forest. Uncle Joe and Aunt Mary are visited by a saint who tells them the whereabouts of all the children who were taken. They'd heard legends from the local townspeople about mystical King's Forest and the missing Rings of Eden but didn't believe them until the children of Eden were taken. The Twins learn about the Crossing, the Remnant Forest, the Rings of Eden and the Tree of Life and its existence on the island of Eden.
They also learn about Solomon the bird of wisdom, bushes of fire, secret caverns with ancient scrolls in them, a hidden sanctuary, horned white lions, Simeon and his most powerful prayer, valley tribesmen, King David, the first war on Eden three-thousand years earlier and much more. They're told that Sargon was defeated in the first war and that he's back for revenge and is seeking the missing Rings of Eden and the Tree of Life.
To rescue their cousins and save the Remnant Forest the Twins must endure attacks and deception from a mysterious man in a red hat and black overalls, from shadow-demons, Sinisters, saber-wolves, Sargon, and Cyrus the sons of the leader of the dark world, a bully named Victor, demon warriors and many others. Fortunately, they're helped along the way by St. Harley, a Magi, brothers Sam and Dan who lead the Remnant Forest armies, Elijah the curator of the Tent of Meeting, Joshua the Minianite, angels, the forests themselves and others. Zak and Sarah follow St. Harley through the Crossing that has shadow-demons tracing through it who are on a mission of their own to stop the Twins from entering the Remnant Forest. St. Harley leads them through the Crossing to the Passage of the Realms the entrance to the Remnant Forest.
The duo is caught in a whirlpool, trapped in a natural living bridge, and Sarah's almost lost to the dark world while in the Crossing. St. Harley and Joshua know much of the history of Eden, and they teach Zak and Sarah about the first war on Eden and how King David wore the Rings of Eden in battle, and they made him invincible. They learn the Remnant Forest was created by the hand of God at a pivotal moment in Eden's history when the Tree of Life was set on fire by Sargon's demon warriors.The duo takes a leap of faith into the Passage and land in the Remnant Forest where they're greeted by a half-man who leads them to the City of Levi where they meet Elijah the curator of the Tent of Meeting and learn more about Eden while looking into the Window of History. They're given a test of faith, they swim through underwater caverns, trek through forest trails that open and close for them, battle demon warriors and find the three-story heart that keeps the Remnant Forest alive. Sargon and Cyrus have a weapon never seen before in the earthly realm. Scepters of Destruction that create lightening and produce fiery tornadoes and wreak havoc on the battlefields. Sargon and his army must climb a mountain to get to the City of Levi and use the Window of History to find the Rings of Eden.Tribesmen fight off the attack of demon warriors as they climb up the mountain and the Twins join the fight with their Mighty Angel and cousins in a final battle armed with spears, swords, arrows, hope and prayer as they fight to win the war between good and evil.