Angels in Battle (Book 2)

(Book 2. First book: The Angel in Me.)
Mitch Grassi, now 22 and dead, is the happiest he has ever been in Angel HQ. With Scott at his side and now facing the same problems as his partner, Mitch thinks he could live a normal life after death.
He finally thought he had everything figured out. But when new threats on Earth start to ruin the Angel systems, they have no choice but to send the most experienced angels down to investigate.
And by experienced, of course they mean the ones who they've sent down and they actually make it back.
What the "experts" don't know is that they will not come back to the once sunny and peaceful Earth they knew before.
Oh no, they will be force to hold a gun for the first time. They will enter danger at every turn.
And what Mitch finds out is most heartbreaking, there's only enough for one job, whether that be surviving or saving Scott.
How will he decide between his and his love's well being without making a sacrifice?