Kaitlyn Parker has no problem being the invisible girl, which is why she finds herself hiding in various cabinets and closets all over her college campus. Despite her best efforts, she can’t escape the notice of Martin Sandeke—bad boy, jerk-face bully, and the universe’s hottest, wealthiest, and most unobtainable bachelor—who also happens to be Kaitlyn’s chemistry lab partner.

Vampiress Roxanne thought that by joining Scanguards as a bodyguard and starting a new life, she could put her painful past to rest. However, old wounds are opened when a new client surfaces, requesting protection for himself and his companion. Charles, a witch, has never been able to forget Roxanne, though duty had forced him to leave her without explanation 23 years earlier. Now he needs her help to save the vampire and witch world from a dangerous force. But saving the world isn't the only thing on his mind. He wants Roxanne back.

Able to render themselves invisible, immortal stealth guardians, like Aiden, have been protecting humans from the dark power of the Demons of Fear for centuries. But the demons might soon have a powerful tool in their hands that allows them to seduce humans to the dark side. The person to provide them with this elixir is the human scientist Leila... Unbeknownst to Leila, the drug she's developing to cure Alzheimer's Disease has the unexpected side effect of weakening the mind's resistance to the influence of demons...

Winnifred Gobaldi and Byron Visser are not best friends. Yes, they’ve known each other for years, but they’re not even friendly. Winnie considers them more like casual, distant acquaintances who find each other barely tolerable, especially when he's being condescending (which is all the time).

Lissianna has been spending her centuries pining for Mr. Right, not just a quick snack, and this sexy guy she finds in her bed looks like he might be a candidate. But there's another, more pressing issue: her tendency to faint at the sight of blood . . . an especially annoying quirk for a vampire. Of course it doesn't hurt that this man has a delicious-looking neck. What kind of cold-blooded vampire woman could resist a bite of that?