Here is the English translation of the paragraph while preserving the original format:

Ning Jie's remorse over his actions, along with Mai Jie's progress in the case investigation. Mai Jie inquired about the truck's serial number via phone and sent Mi Duo Xi's photo to various police stations for assistance. Pi Xiaodong and Ma Yong's investigation revealed that Da Meng and Hong Bin had no social connections, ruling out Mai Jie's first two hypotheses and increasing the likelihood of the third. They also discovered that Da Meng had close ties to Vice Principal Yuan of H University, suggesting Yuan might be an accomplice in Da Meng's crime. Mai Jie received a call from her uncle, Mi Aidong, informing her that Ouyang Yanyan had received instructions from the kidnapper MJ, demanding he board the cruise ship "Bingguo." Mai Jie decided to coordinate a rescue plan with Ouyang Yanyan but found that he and two other children had gone missing, likely acting alone to save Mi Duo Xi. Mai Jie, Pi Xiaodong, and Ma Yong disguised themselves as crew members and boarded the ship but failed to locate the three children. After the ship departed, they realized they might have been deceived—Ouyang Yanyan and the others may have followed the kidnapper's second set of instructions. Forced to retreat, Mai Jie and her team watched as the ship sailed on. Two hours later, near Guangbo Island, someone fell overboard.

(Note: The translation maintains the original paragraph structure and does not include additional descriptions outside the text.)