O'Keefe Family Series by Madeleine L'Engle

When Adam Eddington, a gifted marine biology student, makes the acquaintance of blond and beautiful Kali Cutter at Kennedy International Airport on his way to Portugal to spend the summer working for the renowned scientist Dr. O'Keefe, he has no idea that this seemingly chance meeting will set into motion a chain of events he will be unable to stop. Caught between Kali's seductive wiles and the trusting adoration of Dr... moreWhen Adam Eddington, a gifted marine biology student, makes the acquaintance of blond and beautiful Kali Cutter at Kennedy International Airport on his way to Portugal to spend the summer working for the renowned scientist Dr. O'Keefe, he has no idea that this seemingly chance meeting will set into motion a chain of events he will be unable to stop. Caught between Kali's seductive wiles and the trusting adoration of Dr. O'Keefe's daughter, Poly, Adam finds himself enmeshed in a deadly power struggle between two groups of people, only one of which can have right on its side. As the danger escalates, Adam must make a decision that could affect the entire world--which side is he on? less

A stolen heirloom painting...a shipboard murder...Can Simon and the O'Keefe clan unravel the mystery?Thirteen-year-old Simon Renier has no idea when he boards the M.S. Orion with his cousin Forsyth Phair that the journey will take him not only to Venezuela, but into his past as well. His original plan to return a family heirloom, portrait of Simon Bolivar, to its rightful place is sidetracked when cousin Forsyth is found murdered... moreA stolen heirloom painting...a shipboard murder...Can Simon and the O'Keefe clan unravel the mystery?Thirteen-year-old Simon Renier has no idea when he boards the M.S. Orion with his cousin Forsyth Phair that the journey will take him not only to Venezuela, but into his past as well. His original plan to return a family heirloom, portrait of Simon Bolivar, to its rightful place is sidetracked when cousin Forsyth is found murdered. Then, when the portrait is stolen, all passengers and crew become suspect.Simon's newfound friends, Poly and Charles O'Keefe, and their scientist father help Simon to confront the danger that threaten him. But Simon alone must face up to his fears. What has happened to the treasured portrait? And who among them is responsible for the theft and the murder? less

When sixteen-year-old Polly O'Keefe journeys to Athens, she feels confused and betrayed. The past eight months at home were different from any other time in her life. She met the brilliant, wealthy Maximiliana Horne, who gave her encouragement and made her feel self-confident. Polly idolized Max, until she learned a startling truth that left her wounded and angry.Now on a trip to Greece arranged by Max, Polly finds romance, danger, and unique friendships... moreWhen sixteen-year-old Polly O'Keefe journeys to Athens, she feels confused and betrayed. The past eight months at home were different from any other time in her life. She met the brilliant, wealthy Maximiliana Horne, who gave her encouragement and made her feel self-confident. Polly idolized Max, until she learned a startling truth that left her wounded and angry.Now on a trip to Greece arranged by Max, Polly finds romance, danger, and unique friendships. But can she find a way to forgive Max and remember her as more than a painful memory? less

A flash of lightning, a quiver in the ground, and, instead of her grandparents' farm, Polly sees mist and jagged mountains—and coming toward her, a group of young men carrying spears. Why has a time gate opened and dropped Polly into a world that existed three thousand years ago? Will she find her way back to the present before the time gate closes—and leaves her to face a group of people who believe in human sacrifice?