Campfire

It was a nice sunny Saturday and Lucas, Emily, and James went to camp overnight in the picturesque woods right by their little town. They rode their bikes out and found the perfect camping spot. The two twelve-year-old boys and the thirteen-year-old girl built a fire, and spent the evening telling scary stories. Then, in the pleasant Sunday morning, they wake up refreshed and ready for more exploration.
Strangely enough, the forest is silent. No birds, no bugs, not even the rare fox. It's eerie and unnerving, so they decide to cut their expedition short. But there's no one anywhere, not even back in town. They don't know what to expect, but they surely would never have expected that a time-traveling being from the future needs their help. Will they manage to recover the ancient device he needs, or will the timeline fall into disorder?