Worlds Colliding (Supernatural) Book Eight

Catty and Sabrina Winchester have been on the run for a whole year. They have been fighting against monsters, Demon and Angel alike. They are afraid, they are always looking over their shoulder, and they don't know if they will ever stop coming for them.
Dean Winchester, Ness Singer-Winchester and Castiel have been in Purgatory for that entire year, fighting and killing all of the monsters that have been trying to kill them. But there is also something that happened to her that they can't escape easily.
Sam Winchester has lost Octavia, and now that he had lost Bobby, Dean, Ness, Castiel, and lost touch with Catty and Sabrina because they wanted to keep him safe from afar, he has tried to start a normal life where there is no pain, but it doesn't quite turn out like he wants it to.
Castiel is mysteriously brought back from Purgatory, and he is under control of the Angels to try to take Catty and Sabrina for themselves. But what happens when he breaks that control and the Angels need more help than they thought they did?
Can Sam, Dean, Catty, Ness, Castiel and Sabrina get over their fears, their problems, and try to move on with their future, repairing past mistakes or moving on from past loves?
The Trials are in for the long run. Who will be involved in closing the Gates of Hell or Heaven? What will happen when the Gates are closed forever, and what will the world be like, and what will our dear ones be like?
And will they continue to lose the ones they love or will they manage to get back the ones they've lost?