One of the coolest themes BRIO has ever had must have been Sky Train. There is something mesmerising about seeing another train "float" over a ground-layout. It is a fun way to add an extra dimension to the scene. Sky Train was not an easy product to play with. It was expensive, because every other piece of track needed to be one of the special Sky Train supports, and you were limited in what you could do with it because using switches was not possible.