Hostage Rescue — Chris Hechtl

No happily ever after…
Tech billionaire Eugene Ryans did the impossible; he tamed a wormhole on Earth and stepped through it into a new world. Leading a joint team of civilians and military personnel, they found themselves on the run from a Viking army almost from day 1. Together they braved alien flora and fauna while rescuing 2 princesses repeatedly. The only way home was for the Terrans to help the embattled princesses.
Once the war was won Eugene and some of the civilians decided to remain behind while the remaining Terran survivors returned to Earth. Eugene and the others were bent on bringing modern technology, including modern medicine to the medieval culture in the hopes of bettering all and putting an end to the cycles of war, famine, and disease.
With Deidra wed to Eugene, her younger sister Zara was sent north to the conquered Viking kingdom of Duluth as regent. But Zara found far more than she bargained for, a broken kingdom, destitute by the war without leadership or hope. But she hadn't come all that way for nothing. But stubbornness won't win every battle…