After the Eldest Princess Died, I Lit the Soul-Summoning Incense

Use incense as a matchmaker to understand yin and yang. The first undead I summoned was not the eldest princess, but Xiao Man who fell into the water. Xiaoman said: His Highness's undead soul was blocked by a wall made of incense. Murder cases occur one after another, and turmoil continues. When everyone was checking the Liu family, The real murderer has been spying in secret. But he doesn't know, I know better than him ——What is Tongyou?