Where's The Light. Time Traveler Series, #2

In 1987, Marty Caldwell and Sam Porter are deep in a new experiment when a shocking headline lights up Marty's news-monitor: "Electric Light Never Invented-World Plunged into Darkness!" The world is falling apart as factories shut down and cities go dark. Civilization itself is at risk, and only they can save it. Marty and Sam, best friends and collaborators, have secretly built a time machine in Marty's Bloomington, Indiana garage.
They realize they must use it to stop a mysterious ripple in time that has erased Thomas Edison's invention of the light bulb. The two program the time machine for Menlo Park, New Jersey, October 1879-the critical moment when Edison's team is perfecting the carbon filament. As the machine whirs to life, Sam is anxious about changing history, but Marty is determined to set things right. They arrive to find a rival inventor sabotaging Edison.
The saboteur has planted henchmen throughout the town, and Marty and Sam must dodge suspicious townsfolk while navigating the gas-lit streets and hiding their futuristic gadgets. They are nearly caught by a curious young inventor-in-training named Sammy Turner, but Sam's quick thinking saves them. The duo discovers the saboteur's plan to destroy Edison's lab and steal his research. In a daring midnight rescue, they burst into the lab just as the saboteur sets a fire.
They help Edison save his bamboo filament prototype and precious notes. Marty's scientific know-how impresses Edison, who tweaks the vacuum pump and ensures the bulb's success. The saboteur, exposed and furious, tries to pin the blame on Marty and Sam, but the townspeople rally around Edison. The fire is extinguished, and the invention secured, but Sam and Marty are still at risk if they don't escape quickly.
With the first successful light bulb glowing in the lab, the duo races against time to return to 1987. They dodge the saboteur's final attempts to capture them, narrowly avoiding capture by the rival's henchmen. Marty's unshakable determination and Sam's practical caution drive them back to the time machine just in time. They return to their own era, breathless and unsure of their success, but find the world restored-cities shining bright, history back on track, and the headline changed to reflect the light bulb's invention.
The adventure cements Marty and Sam's friendship, highlighting the urgency, danger, and ingenuity required to preserve one of history's most important inventions. Marty, thrilled by their success, is more obsessed with time travel than ever, while Sam remains skeptical but loyal, forever wary of the risks and consequences.