Treasure Quest: The Elliott Chronicles

Brianna and Seth were planning a 'welcome home' party for their parents, who had been away on an extended archaeological expedition, when they receive a call from their father. He unexpectedly invites them to join them in Israel to chase down a lead on a religious relic. When Brianna and Seth arrive, however, their parents have disappeared. They are given forty-eight hours to find their parents and solve the mystery of their disappearance, a journey that takes them back through time to the first century ad. But, there's a catch. If they fail, they will vanish. Forever. Will they find them in time? And if they do, will it be enough to convince their parents to finally believe the gospel and be saved?