Find Intersections between a single polygon and a feature class?

I am looking for a non-geoprocessor solution.

So, I have searched the forums and Google and have not found what I am looking for. I have a single polygon (which is a dissolved buffer from a different feature class) and a separate feature class that I want to find the intersections between and then delete those features. It appears to me that a SpatialQuery only operates on one feature class.

I am guessing this could be done with a GeometryBag, but then I believe it would also find the intersections within the feature class, which I do not want to delete.

Any help would be appreciated.