Michael Gomez and his best friend, Justin, spent the summer at the Dead Sea with Michael’s dad, a professor of ancient civilizations. Michael smuggled two salt-crusted squirrel bodies home in his backpack. When rain hit them, they rehydrated and came to life. Now friends Michael, Justin and Sadie try to hide married squirrels Merle and Pearl from Michael’s family and the cat, Mr. Nemesis.
As the book begins, Merle and Pearl have just realized they are nearly 2,000 years old. Sadie says they should tell Michael’s dad about the squirrels. Michael rejects the idea for fear he’ll get in trouble, and the squirrels worry about being sent back to the Dead Sea.
Michael agonizes over an upcoming math test. He doesn’t understand fractions and long division, so Pearl decides to figure it out and help him. While Michael is at school, she reviews his math book and urges Merle to busy himself by finding them a place to live. Merle visits all the trees in the area and discovers they’re already inhabited. He finds the floor vents in Michael’s house and crawls through to Michael’s sister’s bedroom. There, he has a scary encounter with Mr. Nemesis and makes a narrow escape.
Pearl tries to help Michael study after school, but the boy is easily distracted. Justin and Sadie decide to go roller-skating, and Michael says he’ll join them. He doesn’t have any cash but vows to pay Justin back with the money Dad promised him for getting a B or above on the test.
Pearl recalls the lazy Thessalonians she knew in the Middle East. She tells the kids how the apostle Paul wrote to the Thessalonian Christians and urged them not to be idle. He told them to stay busy and mind their own business as they looked for Christ’s return.
Merle mentions King Solomon’s warnings about laziness and assertion that those who work will prosper. Pearl concludes that God wants people to work hard and do their best, even where schoolwork is concerned. Michael is unconvinced and decides they should all go skating. As a result of his putting fun before study, Michael flunks the test.
Michael’s teacher gives him a chance to retake the test. The highest grade he can receive is a B. Pearl helps him study hard, and this time, he pushes past the distractions. While Michael is at school retaking his test, the squirrels take to the air vents once more to evade Mr. Nemesis.
Michael gets his B, and the kids and squirrels return to the roller rink for skating and Skee-Ball. But more drama awaits them. Michael’s mother has just seen the squirrels, and the kids wonder how she’ll react. Even worse, the man in a suit and sunglasses who watched them on their flight from the Middle East has reappeared. He seems to be following Michael.