Too Good to Be True is the 11th book in the Sweet Valley High series. This book shows the debut of Suzanne Devlin who would return later on in a Super Edition called Special Christmas.
Ned Wakefield gets a call from an old college friend, Tom Devlin, a diplomat living in New York, who suggests a Daughter Swap for Spring Break. Tom's daughter, Suzanne, would spend a week with the Wakefields, while one of the twins would stay with Tom and his wife, Felicia in their Manhattan apartment. Jessica is most enthralled and begins to scheme to go on the trip, while Elizabeth isn't as intent on going to New York.
After a lot of bickering, Mr. Wakefield does the coin flip, and it turns out that Elizabeth is the one going. Broken-hearted, Jessica moans that she would never leave Sweet Valley, and then realizes that Elizabeth is having second doubts. Here she drops a lie that Lila was interested in Todd, which she really wasn't. Elizabeth gives up the trip for Jessica, who, once more, gets what she wants.
Upon meeting Suzanne, Elizabeth is stunned. She is friendly and far from being pretentious; which was odd for a diplomat's daughter. She begins to get a throng of admirers, and she is never wanting for male attention. At first she is the perfect houseguest, but under the skin, there is a world of difference. Suzanne isn't friendly at all, but very much a self-centered and spoiled young girl, who prides herself on manipulation.
Her first scheme was to steal Elizabeth's gold lavaliere necklace that she always wore, and she hid the precious jewelry in her suitcase.
She wangles a babysitting job from Elizabeth so she could be near Mr. Collins, whom she had gained a crush on. When he refuses her advances, Suzanne decides to spread rumors that he had attacked her. What nobody knew was that she tore her own blouse to make it look like he had attacked her.
The scandal raged all over Sweet Valley, which put his job and livelihood in jeopardy. The night of Lila Fowler's birthday party changed everything though.
When Elizabeth was putting a gift for Suzanne in her suitcase, she discovers her missing necklace. She begins to see that Suzanne was really not as friendly as she seemed. In fact, she and Suzanne had an argument about the stolen jewelry. Realizing that Elizabeth knew that her friendliness was fake, Suzanne decided to make everyone think that Elizabeth was losing her memory again. Overhearing the tumult, Winston Egbert springs to Elizabeth's rescue, when he deliberately trips and spills a cup of punch all over Suzanne's white dress. Suzanne drops her pretenses and screams at him for ruining her dress.
Then she attempts to shift her mask back and tries to be friendly again, but nobody buys it this time, and after all her friends desert her, she breaks down and sobs.
Meanwhile, Jessica meets and falls for Pete McCafferty, Suzanne's boyfriend, and after he shows her around the town, he decides he is going to try to seduce her. When the Devlins see Jessica fighting him off, they throw him out and plan to tell Suzanne what he had done.
After Jessica returns, Elizabeth gives Jessica the gift that she would have given Suzanne. And things return to normalcy with everyone.