This is a strong anxiety and fear. Being chased is a real fear response, probably related to witnessing a traffic accident. Suppose the dream house is your heart, your heart. Then there is such a strange man in your heart, but you don't accept him in your heart. You are afraid of him, so you keep running away and want to go to other people's homes (hoping others will give you spiritual comfort), but you only got a little help when you were in the seventh house, but it didn't work. You are afraid that this person will steal your bike (what does a bike stand for in reality) and be destroyed together with your beloved bike. Maybe this person is the epitome of the traffic accident victim. What you need to know is that other people's traffic accidents have nothing to do with you. If you witness these things, your life will not be affected, and your life will not be involved in the accident (losing your bike).
As for what a flying saucer is, further analysis is needed.