Pretty Dark Nothing Series by Heather L. Reid

It’s been twenty three days since Quinn has slept for more than minutes at a time. Demons have invaded her dreams, stalking her, and whispering of her death. The lack of sleep and crippling fear are ruining her life. Energy drinks and caffeine pills don’t make a dent. When Quinn dozes off in the school hallway, Aaron, an amnesiac with a psychic ability, accidentally enters her nightmare... moreIt’s been twenty three days since Quinn has slept for more than minutes at a time. Demons have invaded her dreams, stalking her, and whispering of her death. The lack of sleep and crippling fear are ruining her life. Energy drinks and caffeine pills don’t make a dent. When Quinn dozes off in the school hallway, Aaron, an amnesiac with a psychic ability, accidentally enters her nightmare. The demons are determined to keep them apart, and Aaron from discovering the secret locked away in his memory. Together, they could banish the darkness back to the underworld for good. That is, unless the demons kill them first. less

It’s been five weeks, two days, and eight hours since the demons forced Quinn to throw herself into the raging river, since Aaron sacrificed himself to save her, since his body disappeared without a trace.Everyone wants Quinn to move on, but she can’t, not after a spirit appears to her at Aaron's memorial, convincing her he’s still alive... moreIt’s been five weeks, two days, and eight hours since the demons forced Quinn to throw herself into the raging river, since Aaron sacrificed himself to save her, since his body disappeared without a trace.Everyone wants Quinn to move on, but she can’t, not after a spirit appears to her at Aaron's memorial, convincing her he’s still alive.When a mysterious box materializes on the very spot Aaron disappeared, Quinn finds she’s at the center of an ancient prophesy of betrayal, revenge, and sacrifice that takes her to the depths of the underworld to face Lilith—Adam’s first wife.If Quinn can stop Lilith from unleashing the demon horde Eve, trapped inside the box during the Battle of Eden millennia ago, she will save the human realm and free Aaron from an eternity in torment.All it will cost is her blood. less