Three weeks without a time-travel mission has Abigail feeling incredibly restless. Thankfully, Monday has arrived, and Mr. Caruthers has a new puzzle for class 305. He asks what would happen if Alexander Graham Bell simply gave up on inventing the telephone. Abigail and her friends immediately grab their time-travel gadget and blast back to the year 1876. They expect to find Professor Bell hard at work on the phone, but instead, he has abandoned the project completely for a completely different invention. The third-grade team must figure out how to reconnect the stubborn inventor with his famous idea. Convincing a brilliant mind to change course is a massive challenge, and the clock is ticking. The kids will need to use their best problem-solving skills to help Professor Bell make the breakthrough that changes the way the world communicates.