Lucid Sanctum by E.J. Darling

In Sanctum, nothing is as it seems.
The detoxed are being hunted down, and the Underground is scrambling to find freedom beyond the wall. Cory Michaels has one job—get her family out. But the quickly thought out plan shifts when her daughter turns up missing, and Cory refuses to leave without her child. Thankfully, she isn’t the only one who stays behind.
But not everything is as it seems. As her mind starts to unravel, as the puzzle pieces begin to line up, her world is flipped on end.
While the stakes only get higher, Cory must find the strength to move forward, to get what remains out of Sanctum’s vice. She’ll do whatever she has to in order to make that happen.
Even in the face of despair, one must choose strength.