The continuing uncertainty over Planet 9

I didn't think it would be so hard to work our whether there really is Planet Nine - but it obviously is. 

Planet Nine is dead; long live Planet Nine? For some years, scientists have debated the existence of an unseen planet at least five times the mass of Earth in the outer reaches of the Solar System. Now, the hypothesis has been dealt a blow by a new analysis of distant, icy objects, which questions the evidence that they are under the gravitational pull of a huge planet.

The findings do not rule out the possibility of a ninth planet orbiting the Sun, and astronomers say more data will be needed to put the debate to rest.

 I would like it to turn out to be a captured black hole, actually.   That would allow for some good science fiction ideas.