In The Search for the Lost Prophecy, the sequel to The Secret of the Scarab Beetle, Horace continues to search for more information about the Time Keepers and his role in this secret order. After he discovers that the tree portal at his grandparents' farm is destroyed, Horace, along with his friends Anna and Milton, travels back in time to 1920s Detroit, hoping to learn more. There they meet keeper Herman at the Scarab Club and learn that someone is threatening the Time Keepers and the order's mission. Horace finds out that the mystical Benben Stone is being stored in a crypt back in present-day Niles, Michigan. And Horace is now tasked with keeping the sacred stone safe. Will the person or persons threatening the Order learn of Horace's true identity?