Abstract -- The original negative of the Costa Rica film of an oval aerial disc-like object was obtained and carefully analyzed. Not only was there no evidence of optical defects, deliberate hoax, or support for other prosaic explanations for the disc image, but also interesting new surface details were found, all of which possess the same oblique orientation. The disc-shaped object remains unidentified.

In our original article, "Photo Analysis of an Aerial Disk Over Costa Rica" (Vol. 3, No. 2, p. 113-131), we concluded by saying that we were trying to obtain the original negative of the unidentified object, photographed by chance during an aerial mapping mission for further study. Indeed, we were concerned that some of our reviewer's suggestions might require stricter tests than we could carry out on a second generation negative. We are pleased to state that through the efforts of Peter Sturrock, Jacques Vallee, and Ricardo Vilchez in San Jose, Costa Rica, we received three connected frames (No. 299-301) of the original black and white negative on February 11, 1990.

As one would expect, there is more fine detail visible on the original negative than on the copy and this detail is highly interesting. Several points deserve further comment based on careful unaided and magnified visual inspection of this new negative and different contrast positive print enlargements that were made. Figure 1 is a high contrast enlargement of the disc made from the original negative.

First. The oval disc image is present in the same relative location on frame 300 as already described in our first article. Also, the entire film plane on frames 299, 300, and 301 is flat with absolutely no protrusions or depressions anywhere. The thoughtful comments by our original reviewer in this regard were shown to be unsupported.

Second. The emulsion side of frames 299 and 301 possessed several small, irregularly shaped developer stains which only affected the specular reflectivity of the emulsion, but did not in any way influence the transmissivity of the film. These stains were completely invisible except when the film was