My guest is the emperor

Top tour guide Su Wanwan accidentally time-travels, and her phone mutates into a tour guide mirror that can foresee life and death three days ahead. While running a street stall, she encounters the 'useless third prince' Gu Zhao, and the mirror unexpectedly reveals the shocking secret that he will ascend the throne in three days. To protect herself, she is forced to bind with Gu Zhao, using her DNA-encoded tour guide abilities to anticipate crises and dismantle deadly traps, accompanying him from hiding in the deep palace to ruling the world. When the mirror shatters and her golden abilities vanish, she realizes that they have long since become each other's irreplaceable lifelong companions.