Castine, Bittersweet Outcome - Part 4 is the final installment of the Castine Series. Bittersweet Outcome begins exactly where Castine, Then There Were Two - Part 3 leaves off. With Phaelan not quite the same as he used to be and Alison having barely recovered from her injuries, the future of Castine appears less hopeful than it once was. Having an inexplicable bond with the creature, Alison still flashes upon the Maraudulv without warning causing worry among the others. Her fears of an imminent attack are justified when she flashes on the two Maraudulvs readying the Lugwarts for battle.

Now Alison and her family prepare alongside Marbellia and Phaelan and their allies for the battle of their lives. With war raging on so many fronts, their faith in each and their abilities will be tested like never before.

And in the end, when the dust settles and the smoke clears, will Alison be able to do what needs to be done? Will she say goodbye to the one she loves? Will she be able to find the way home?