The Mystery of the Hollow Oak

In the small, quiet town of Milton, nestled between marshy forests and the Oregon coastline, stood a remarkable 150-year-old oak tree, known as the Hollow Oak rumored to conceal an age-old secret. Our protagonist, 12-year-old Sam Wringley, was an adventurous boy fascinated by mysteries and legends, the tale of Hollow Oak was amongst his favorites.
Sam's fascination began when his grandfather shared tales of a hidden treasure buried by the town's founder Jeremiah Thompson, inside the hollow of the Oak, a century back. Intrigued, Sam resolved to uncover the truth.
One sunny afternoon, armed with his little sister's pink torch and granpa's rusty Swiss knife, Sam approached the towering Oak. Crawling into the hollow, he immediately felt a chill run down his spine. He noticed odd symbols, patiently carved into the inner bark.
With the help of his tech-savvy friend, Elsie, Sam photographed the symbols and started to decipher what they meant. After weeks of late-night gatherings researching ancient symbols, viewing documentaries and libraries visits, they stumbled onto some resemblances in Celtic symbols. The sequence somehow indicated latitude and longitude, the coordinates led to 'The Witches Point', a cliff overlooking the sea just outside town, famously known as a spot for Jeremiah Thompson's silent musings.
Fueled by the thrill of adventure, Sam and Elsie decided to visit the spot. Armed with their backpacks and maps, they embarked on their expedition one Saturday morning. The journey through the dense forest was quite challenging, yet their determination overpowered their fatigue.
Reaching at the cliff, as they looked around, Elsie spotted a cave partially concealed by overgrowth. They discovered another set of symbols inside, identical to the sets in the Hollow Oak. Sam remembered his grandpa's stories where it said, the treasure is hidden 'where it all began.' He quickly realised that this was Jeremiah Thompson's original home, where the town of Milton had started from as grandpa had once told.
They begun to search the cave frantically and eventually, hidden in a corner under a fissured rock, they found a rusty old chest. With pounding hearts, Sam used his granpa's knife to break the lock and they lifted the lid. As moonlight streamed into the chest, they saw it filled with old county bonds, gold coins, antique jewellery and Jeremiah Thompson's long lost diary.
The news of the treasure discovery spread like wildfire in Milton. The Wringley's were celebrated as heroes, the found County bonds benefited the public schools and infrastructures, while the gold coins and antique jewelry was donated to the town's museum. The age-old mystery of the Hollow Oak had finally found a dramatic conclusion.
Though Sam and Elsie had resolved the famous mystery, their portray as town heroes was short-lived due to their young age. Yet, they weren't disheartened. They knew they had embarked on an unforgettable adventure, found the unknown and created a childhood memory they would cherish for a lifetime. Moreover, they learnt that the real treasures were not gold or riches, but their friendship, courage and thirst for knowledge. As for the Hollow Oak, it stood there silently, its secret revealed but its grandeur unaltered, a timeless emblem in the heart of Milton.