Hope Everlasting. The Variant Saga, #3

Terry is on the run, having escaped from prison and killed its overseer. He and his friend Ludo need to find a way to get to the northern border. That's where Ludo's wife is being held, but time is of the essence. If they don't hurry, she'll be sacrificed to the gods as part of some barbaric ceremony. With an army at their heels and a continent to cross, Terry and Ludo will need all the help they can get.
Meanwhile, Mei Curie has opened a portal to another world.and it isn't what she expected. There are worms the size of cars, animals with bulletproof hides, and an advanced alien race unlike anything mankind has ever witnessed. Not to worry, though. Johnathan Finn has just the ticket: a rifle stocked with bullets, ready to deal with whatever threats come knocking. Along with his team of soldiers, John is here for a single purpose-to find his missing friend and bring him home-but in a world as strange as this one, a simple search and rescue mission could prove deadly.
Experience the third volume in the epic series from USA Today Bestselling Author J. N. Chaney. If you're a fan of Ender's Game, Fallout, or Renegade Star, you're sure to enjoy the Variant Saga.