Mary Downing Hahn
Author
Summary
"When best friends Abbi and Skylar witness a clandestine meeting between a mysterious woman and someone in a dark van, they're thrilled. Finally, a mystery to spice up the summer! Who could these people be? Why are they meeting? Are they spies? Criminals? The two girls are determined to find out. But then a local woman goes missing and is found dead in the woods. And Abbi and Skylar realize that their detective work could hold the keys to solving...
10) One for sorrow
Author
Summary
"When unlikeable Elsie dies in the influenza pandemic of 1918, she comes back to haunt Annie to make sure she'll be Annie's best--and only--friend soon"--