When I began my tour of the Orion galactic arm, there were the usual "must-see" attractions including the palaces of Tirrell and the argoshalt herds of Doranel. There were also lesser-known places of natural beauty. The golden rings of Trastel 3 and two unusual features in the system of Sol: the amazing red spot of its fifth planet and the phenomenal reappearing hexagon of the sixth. I was unlucky with the latter on my arrival but witnessed it during a later visit. How can such a geometric shape appear in nature? Apparently, it's caused by the interaction of the jet streams in the clouds, but it looks, for all the world, like something nature could never have had a hand in.

During my visit to Sol, I stayed in the outpost on the fourth planet; a dry, dead world known locally as Mars. It was cold, had no atmosphere, and no obvious attractions other than a very long, deep canyon. Why the Federation had a settlement here was a mystery to me until, one night, after too much beer and a successful game of dimplert in Bar Maximus, I got a ship's first mate, a Vestal, to open up to me.

He told me the beautiful third planet, known as Earth was being watched, to ensure it wasn't infringing any of the Federation's prohibitions.

I'd never heard of Earth or of the Federation prohibiting against any world. Prohibiting what? I was immediately intrigued.

I probed for additional information, but I think he'd already divulged more details than were strictly allowed. No one else in the bar would talk about Earth at all, so I could get no confirmation or denial of the first mate's claim. I resolved to hunt him down the next day.

Late morning, I managed to find the Vestal, but he refused, point blank, to say more once he'd sobered up. I went to the local spaceport and asked a freighter operator if I could get a ship to Earth and was looked at as if I were insane. The answer was no. It was illegal.

Trying a different tack, I asked if I could get a close look at the planet from orbit? The answer was yes, but it wasn't on any direct route used by the operator. I offered to pay for the fuel, and he said he'd take me in four days' time when he'd nothing else of interest on his agenda, as long as I didn't mind being stuck on the freighter while it collected supplies from a nearby star system.

I was impatient and spent the intervening time trying to discover more about the planet. There was very little information. Actually, that wasn't true. There were lots of files, but almost all had been redacted, leaving just the file name on the Frame but no content.

One file I could download was a video. It called itself a documentary and was presented by a person called David Attenborough. Although I couldn't understand the language, the images were fascinating. It dealt with the ocean life of the Earth and the diversity was quite extraordinary. This enhanced my curiosity about this mysterious world.

Four days later, I transferred the promised afeds to the skipper and the freighter, an ancient D-class rust bucket, set off from Mars. Its intermittent quantum drive and failing artificial gravity meant an uncomfortable and slow trip. What should have taken a few hours dragged into almost three days.

Eventually, the freighter hung above the Earth, in a low orbit, and the view explained why the title of the Attenborough video had been translated as Blue Planet.

It really was a beautiful blue world, probably more than fifty per cent water. The operator gave me six orbits, and as we passed over the night hemisphere, I was staggered to see the magnificent network of lights illustrating the coming and going of the species which lived here. Jewel-like clumps were cities and towns. The population must be in the billions. The seas were dark, apart from occasional dots of light. How I'd have loved to be allowed to sail this planet's huge seas and oceans.

After a delay while produce was loaded at Wierala, a week or so later, we returned to Mars and further research on the Frame led me to discover the name of the last Federation ambassador to deal with the planet. He was Hareen Trestogeen and lived on Pestoch. I immediately booked a flight.

Pestoch was in the same system as the Federation capital, Arlucian. It was a very busy world, packed with universities and engineering colleges. I had trouble tracking down the ambassador, the reason being that he'd sadly died at quite an early age. However, Ambassador Trestogeen's family threw open his files to me. Even better, they allowed me to work in the ambassador's office. I was faced with hundreds of papers, video and audio recordings, plus lots of personal notes, which would help me fill in gaps in my knowledge. A researcher's dream environment. Among it all, I discovered souvenirs of an earlier diplomatic team's time on the planet and many photographs of the residents; a bipedal called humankind.

During the first year on Pestoch, yes, I was there that long, I did little but try to understand the sequence of events. The more I discovered, the more fascinated I became. I took two months out to concentrate on learning English and that opened up my understanding of more of the files. Most Federation languages could be esponged into the mind within an hour but searches of the Frame for the program for English drew an absolute blank. Puzzling, because it was obvious from the files that ambassadorial staff all spoke the language. Once I'd learned it the old-fashioned way, I found correspondence, videos, and audio recordings in the planet's language. Ambassador Trestogeen had apparently done everything in his power to be inclusive with this species. Why had he failed?

Humankind comprised a warm-blooded animal with one head, two arms and two legs with a central torso. There were two sexes and several colour variations. In addition to a variety of skin shades, they had hair or fur of even more colours, although some, like purple, pink, bright blue, and green, were apparently unnatural. Strangely, while some males had a little body hair, the bulk of it was on their faces and heads. Females, however, had virtually no body hair but sported the most extravagant, flowing locks on their heads, manipulated into amazing styles.

Humans spoke in a huge number of tongues, but Federation interaction was usually in English or French. The latter being a beautiful sounding language which I might try to learn if I found more material written or spoken in it.

What follows, I decided to write as a dramatised account of events. I wanted to bring it alive for the reader. Inevitably, this meant that much of the dialogue had to be reconstructed from stories, minutes, documents and, to be honest, a hefty dollop of guesswork. I tried to look at events from various points of view and to recount individual's stories from their perspectives. My research into species and individuals has helped me do that, but the process is likely to be imperfect. However, I'm confident that I've correctly pieced together the overall story of the only planet I'd ever heard of to be denied Federation status.