Star Skeleton Sword Mark

Only a few people know: Over the past two hundred years, the number of "doors" has increased. When the first batch of colonial ships lost contact, there were only three of them. Now, at least twenty-seven of them have been detected at the edge of the solar system. They float silently in deep space, and the curvature of space and time around each door slowly changes, as if they are breathing. No one knows when the door will open again