The Secret/Temperance.
In fact it's, as some previously said, the only way not to sacrifice other people.
In my point of view, V can't stand anymore loss because of her. Losing Jackie was too much for her and she didn't want to feel it again and worse feeling guilty to inflict this to the people who cares for her.
The only thing that disappoint me is the lack of choices.
You can't let people know what you intended to do and have a message for them.
So it add frustration to the sadness...
But it's still more true to the idea I have of V and what she finds most important.