Out of Sight — Trish Milburn

Jenna McCay is a street cop in Nashville when a secret government agency discovers her ability to make herself invisible and coerces her to come work for them in exchange for information on her missing father, a soldier who disappeared overseas when she was young. She's thought him dead all these years, but this agency has information pointing to the possibility that he's still alive. But she has to go undercover in the White House to get that information from them. Her job is to find out who inside the White House is threatening the president. Jenna also has to deal with her attraction toward and suspicion of the agent assigned to her, Daniel Webster (and yes, that's his name, a fact of which she makes fun). In the course of the investigation, she discovers the source of her ability, and that it's related the Project Athena experiments that were done on soldiers, her father among them.