"Wait Till Helen Comes" is a ghost story.
(Copied from Wikipedia)
The book begins with a stepfamily moving into a new house located in the country. The house was originally a church, so it still has a graveyard located out back. The previous owners converted it into a house. The stepfamily has been having problems. Heather's father, Dave, married Molly and Michael's mother, Jean. Heather hates her stepfamily and causes problems, hoping it will cause Dave and Jean to divorce. Moving into their new home only makes their problems worse. The graveyard is haunted by a lonely ghost named Helen Harper. Helen and Heather are the same age, seven-years-old. Both of them were involved in fires. Both of them lost immediate family members to those fires. Helen quickly realizes Heather is just as lonely and miserable as she. She tells Heather that she, Helen, is the only one who will ever love and accept her, no matter what Heather does. As sign of friendship, the ghost gives Heather the locket Helen wore while she was alive. Molly is the only person to discover Heather's new friend.
Soon, things become very tense for the entire family. Heather starts to lie even more about her stepbrother and stepsister, which causes their parents to take sides and to fight more often. Heather also starts threatening her stepbrother and stepsister. She tells them Helen will come after them and their mother. This threat eventually comes true. While everyone was out one day, Helen comes to the house and destroys all of the stuff belonging to Molly's side of the stepfamily. Molly and Michael also argue about Helen's existence. Molly would show him clues pointing to Helen's existence, such as proof that Heather sneaks out of the house in the middle of the night and go to the graveyard. When Heather realizes they're trying to find proof of Helen's existence, she gets them in trouble by telling her father they're spying on her. Molly tries talking to her mother and stepfather about Helen. They will neither listen to her nor believe her. Instead, they think she has an overactive imagination and is just overreacting to the graveyard located near the house.
Michael takes Molly to the library. He wants to research local history in order to prove that Helen never existed. However, they find out that Helen really did live about 100 years ago, and that her mother and stepfather died in a house fire. Helen was in the same fire, but she managed to escape. Unfortunately, she fell into a pond outside the house, where she drowned. A librarian tells them three other children have drowned in the same pond since Helen's death. Mr. Simmons, the caretaker who cares for the graveyard, tells the siblings the same story about the drowned children. Later, Mr. Simmons privately tells Molly that his sister believed a cousin of the Simmons family was murdered by Helen's ghost. Molly realizes Helen has a dark plan for Heather: she wants to drown Heather so they can be together forever.
A few days later, when Jean and Dave went into town, Heather disappears. Molly realizes where she went: to the house where Helen and her family died. Molly heads to the house, which is currently abandoned. It begins to sprinkle, and eventually starts pouring. Molly overhears her stepsister talking to the ghost. The ghost is becoming impatient with Heather. Heather doesn't want to drown herself because she's scared and doesn't want to leave her father. Helen says Dave stopped loving Heather when he married Jean. The ghost goes on to explain how much happier Heather will be after she drowns herself and they can finally be together forever. Heather finally agrees to do what Helen wants. They head to the pond. Both of them jump in. Molly jumps in after them. Helen realizes Molly's trying to save Heather. The ghost attacks Molly as she pulls Heather's head above water. Molly stops the attack by pulling the locket off Heather's neck and throwing it as hard as she can. The ghost chooses to save her locket over attempting to drown Heather. Molly drags an unconscious Heather to the shore and performs mouth to mouth resuscitation on her. Heather wakes up. She sees Molly and frantically tries to jump back into the pond. Instead, Molly drags her into the house. It's raining so hard by now they have to wait for it to stop before going home.
When they go in the house, the floor collapses. The girls fall into the basement. Molly finds two skeletons down there. They turn out to be Helen's mother and stepfather. Heather explains Helen accidentally started the fire that burned the house down. Helen and her stepfather were arguing. Helen knocked over an oil lamp, which started the fire. Molly realizes that Heather's mother also died in a fire, and asks if she accidentally started that fire. Heather admits she did. She was playing with the stove, but didn't realize the danger because she was only three-years-old. The girls continue talking and come to terms with being a stepfamily. Helen eventually floats down into the basement. She is so overcome with grief, that she completely ignores Molly and Heather. This is the first time Helen has been able to locate the bodies of her parents. She touches their skulls and cries over their deaths. Her mother's ghost appears. They embrace. Both of the ghosts disappear. Heather realizes that if Helen's mother could forgive her, then her own father can forgive her for the accidental death of her mother. Many hours later, Dave, Jean, and Michael come. They pull the girls out of the basement and take them home.
Heather tells her father she accidentally started the fire that killed her mother. He understands it wasn't her fault. The family is able to be a true family and get along. Helen's parents are buried next to her. A few days later, Molly and Heather find Helen's locket hanging on a statue near her grave. They believe it's a present from the ghost. In the locket, there's a note with a message: "Do not forget me. -Helen." Helen is finally at peace.
- Helen-The ghost of a lonely young girl who died drowning in a lake when she was about 7 years old. She is the books main antagonist.
- Heather-A bratty young girl who doesn't have any friends. She befriends Helen, only to find her and her sister in trouble. She is another antagonist.
- Molly-The man protagonist. She has to save her stepsister from being drowned by Helen.
- Michael-Molly's brother. He's another protagonist. He enjoys science.
- This story takes place in 1985. Helen died in 1885, a 100 years prior to the story.
- This story was published in 1986.