A positron excess - uncovered by a cosmic ray detector - could point to dark matter. Or to a pulsar. Or to a supernova explosion.
Or....? It sounds like the makings of a good and debatable book. A lot of "meat" but no decision yet. For now, the positrons - like the edges of our Milky Way - are collapsing off in unexpected directions. And a lot of "might be's" are providing fodder for further debate.