In Order to Get Out of Prison, Develop Baidi Air and Space Fighter

A paper letter marked by Baidi Air and Space Fighter was mailed to Longhang Yifei. "Is this a concept that was proposed ten years ago? I didn't expect anyone to actually complete it. Where is the person who sent the letter?" "Based on the mailing address, it seems to be in Star City Prison." "Quickly, call and ask what's going on. We must find this person." "Chief Master Tang, can this really be produced?" "According to the existing drawings, it is completely feasible, but the specific plan still requires this person's help." This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.