The Red Pyramid by Rick Riordan. When Sadie and Carter Kane are siblings, but one lives in London while the other travels the world with their father. When the Kane’s father decides to get the children back together, he accidentally releases an Egyptian god named Set. The Kane children have to save their father and defeat Set, and keep him from taking over the world.
One of Rick Riordan’s good books
5 out of 5 stars.