Tuck Everlasting

Tuck Everlasting is a whimsy tale of immortality. A girl is "kidnapped" by a family. However, they just want to befriend her. They have drunk from a spring and now cannot age or die. They don't want other people to drink from the spring. However, a man in a yellow suit wants to bottle up the spring water and sell it. He trick's the girl's family into signing over the property in exchange for delivering her back. In an altercation with the family, he is hit and eventually dies. This leaves the possibility of the gallows - which would not be pleasant for somebody that can live forever. However, the girl helps them escape. She also helps toad become immortal via the spring water. At the end of the book, the family visits the girl's grave. She had lived a full life. They also spot the toad, who is now ambivalent to any vehicles that may cross the road.
The book presents immortality as a lonely experience. How can you really have life if you don't have death?