You do not have this one. Almost nobody does. If it appeared in your report, something is being read as natal that is not.
What it looks like in a life
Neptune and Pluto were ninety degrees apart around 1815, with Neptune in Sagittarius and Pluto in Pisces. Everyone born in that window shared it, and none of them are here. The next square falls in roughly the 2060s. So what you are looking at is almost certainly a transit: Pluto squaring your natal Neptune, or Neptune squaring your natal Pluto. Both happen once in a life at most, and both run for years. They land the same way. Something you have believed in, leaned on, or used to blur the edges gets pressure applied to it until it fails, and what was underneath comes up whether you are ready or not.
The gift
A square builds muscle. This one builds the muscle that holds a person together when the story they were living inside stops working. Neptune keeps offering the escape and Pluto keeps refusing to let the escape be free, and between them you find out what in you is actually load-bearing. People who go through this stop needing their illusions to be true.
The friction
The loop runs underground. You dissolve something rather than end it, then the ending happens anyway and takes more than it had to. Substances, fantasies, and rescue stories get used as anesthesia for a change that is already in progress. The more the fog is defended, the more force is required to clear it.
The esoteric layer
Neither planet was known to the ancient astrologers, so nothing here comes from that lineage. The esoteric framing is Bailey and modern. Bailey puts it plainly: the triangles indicate possibility, the crosses indicate process and points of crisis. The square is the number four, the cross of matter, where friction produces something real. Bailey counts Neptune sacred and sixth ray, devotion whose task is the dissolution of the separate self, and Pluto non-sacred and first ray in its destroyer function. At right angles, the surrender and the ending fight until the person stops confusing them.
Where this goes
If this is transiting your chart, the houses involved say what is dissolving and what is ending. That is exactly the material a therapeutic astrology session is built to work with.
Related
See it in your own chart
Cast your chart free and read this placement next to everything else you carry.