Keepers of the Labyrinth #1 by Erin E. Moulton

Lilith travels to Crete to attend a two-week conference for Future Leaders International. Teens from around the world are grouped into teams of four that will compete for scholarships. However, Lil and her new friends quickly discover there's something more serious going on. Lil sees their mentor holding a "key" that looks very much like a necklace her mother once wore, before she committed suicide. Lil and her team are thrust into a dangerous conflict, as they tumble underground into a labyrinth. The maze is marked by confusing clues, and incorrect decisions are deadly. The path leads to a powerful treasure from Zeus, and his worshippers are willing to kill to get their hands on it first.

The plot is based on Greek myths, but the author adds a unique twist. This book describes the origin of the myths as being based on humans who actually existed. The plot reads more like an adventure than a fantasy story. It often hints at supernatural powers and characters, but everything can be explained by science. So far. The mentors are guardians of archives that hold the secret to immortality. Another unique aspect of this book is that all of the main characters are females. The four mentors and four young girls are the protectors of the labyrinth. It's a nice change to see females play such a big role in an adventure book.