No one has ever accused Sage Cunningham of being easily distracted. She has a plan, and she won't be swayed. She'll spend the summer interning in her mentor's lab in Amsterdam, and then she'll be ready for college. All she needs to do to pay for the summer abroad is agree to serve as the au pair for Dr. Reese's three-year-old. Sage has it all down to a science, but she doesn't anticipate the surprise arrival of Dr. Reese's teenage son. Ryland is spontaneous,...