The Reunion (The Vampire Diaries, #4) by L.J. Smith

Elena, brought back from the dead, calls on Stefan and Damon to recreate their powerful vampire trio. Together they must face incredible evil and battle against it with their combined strength, cunning and charm - only then can they find peace, and save the friends they have left behind...

About the Author
L. J. Smith is the author of more than twenty books for young adults, including the bestselling Vampire Diaries and Night World series. She lives in Northern California, in a rambling house in a small town. Lisa knew that she wanted to be a writer since she was about six, when a teacher praised a poem she'd written. She wrote her first book in high school, finishing it in her first year of college. Then she became a special education teacher before she became a writer full-time.