This 6th novel in the Tom Swift Invention Series brings back some of Tom's old acquaintances: his Space Friends. Since their first interaction several years earlier, Tom has tried to get them to provide details about themselves so he can assist them in their mission to visit the Earth. Until he makes a surprise advancement in how he "reads" their symbol messages, he has had frustration after disappointment trying to get them to tell him anything of substance. Now that he has an understanding he is horrified to find that their "masters" have declared their mission to our solar system to be a failure and will be recalling them, forever, in just a few short weeks. Now he races against time trying to develop both a vehicle and an environment capable of supporting them. Just when he thinks he has succeeded, disaster strikes. Not only is his new flying environment destroyed, but now the Masters insist the Space Friends won't be the ones coming for a visit, it will be them! Tom knows that can't be allowed and so he must work overtime to complete a new environment, be a diplomat and get ready for the visit.