In the first part of The Oath - "Alone," Paul and Karina escape their ravaged and overrun camp, but a mortal injury sends them on an urgent mission to find medical help.
In the second part of The Oath -- "Choice," Karina encounters an unexpected survivor in the medical facility as Paul's health deteriorates.
In the third and final part of The Oath -- "Bond," Karina and Paul are forced to make life and death choices.