If destiny was changed by a third party. If two persons meant for each other were separated. Would destiny be able bring them together again?

Chen dynasty, Jiankang. The emperor and empress couldn't have children for unknown reasons and so they adopted a pitiful looking baby from Korea. 18 years later, Shixun was acting strange, causing them to think they have failed in raising him to be a good heir. What did Shixun hide from them?