What is the plot in the book The Magnificent 12 The Call?

In "The Magnificent 12: The Call," the main character Mack is chosen to be part of a group known as the Magnificent 12 who must save the world from an evil force. He must collect powerful relics and unlock his hidden powers to fulfill his destiny and defeat the enemy. Along the way, Mack faces challenges and enemies that test his bravery and strength.