I think I have a stray vertex?

I don't no why you can't select and delete it, but I highly suspect that it is not a stray vertex, but part of the (hidden) chest. 

Un-hide everything to see where it belongs to. Do not delete. As you can see in the UV Editor, it is connected to something.

I realized that the "stray vertex" I thought I was seeing on the object view was just the object origin, set to an odd spot (I'm very new to Blender!). I've isolated the problem vertices on the object (selected in the image) that unwrap oddly, but I can't figure out why they would be causing issues. 

Thanks for the help!

OK, resolved on my own. For reference, if other people look at this, the problem was an extra set of verts and edges along that side that I somehow created in the midst of modeling. Once I found them and removed them, all was well.