It posits a speculative evolution of dragons from the Cretaceous period up to the 15th century, and suppositions about what dragon life and behavior might have been like if they had existed and evolved. It uses the premise that the ubiquity of dragons in world mythology suggests that dragons could have existed. They are depicted as a scientifically feasible species of reptile that could have evolved, similar to the depiction of dragons in the Dragonology series of books. The dragons featured in the show were designed by John Sibbick.
The program switches between two stories. The first uses CGI to show the dragons in their natural habitat throughout history. The second shows the story of a modern day scientist at a museum, Dr. Tanner, who believes in dragons. When the frozen remains of an unknown creature are discovered in the Carpathian Mountains, Tanner, and two colleagues from the museum, undertake the task to examine the specimen to try to save his reputation. Once there, they discover that the creature is a dragon. Tanner and his colleagues set about working out how it lived and died.
The docufiction starts with a live-action dramatization of the discovery of a frozen dragon carcass in the Carpathian Mountains in Romania, next to similarly preserved bodies of some 15th-century would-be slayers. The drama then starts in present-day Montana with a battle between a prehistoric dragon and a Tyrannosaurus rex, 65 million years ago. Then a 6 mile-wide meteorite crashes into Earth, killing almost all large life forms on dry land. However, "marine dragons" evolve in the sea. The story then goes that around 64.95 million years later, mammals have taken over the planet, humans being among the most perilous to dragons. The final scene returns to 15th-century Romania, where a lord and his squire enter an icy cave to fight the "monster" that has been stealing sheep.
A large part of "Dragons" is devoted to sciency explanation of how a 900-pound animal could have flown and breathed fire from its mouth.
The Scotsman opined that The Last Dragon's computer graphics made it "awesome", but the film was full of "filth", "never scary" and yelled "Do not believe this slice of old hokum" at the viewer.According to The New York Times "it's easy to forget that it isn't a serious documentary" after the fiction disclaimer at the beginning, judging the computer graphics to be well made, sometimes beautiful, but not impressive "to the point of wonder".
The story begins 65 million years ago, sometime during the late Cretaceous period. A Tyrannosaurus rex is stalking a creature that has been raiding its territory and food sources. The creature is revealed to be a juvenile prehistoric dragon. The T. rex had not eaten for several days and prepares to attack the young dragon: in an attempt to defend itself, the dragon extends its wings to give the illusion that it is much larger than it really is, but the T. rex is not convinced and continues to advance. The young dragon then tries another tactic: it utters a piercing scream that carries for miles. Although the screech disorientates the T. rex, hurting its sensitive ears, the attack only goads the dinosaur on. Suddenly, the dragon's mother swoops down from the sky to the rescue and attacks the T. rex, slashing the dinosaur's skull with its talons. During the short fight, both animals cause serious injuries to the other; the T. rex breaks the female dragon's wing and in retaliation, the dragon breathes a jet of fire at the Tyrannosaur's face. The Tyrannosaurus limps away with fatal burns, while the female dragon is left unable to hunt for herself or her offspring.
65 million years in the future, at the London Museum of Natural History and Science, England. Dr. Jack Tanner, a young paleontologist, who has been fascinated with dragons since childhood is introduced. Upon discovering talon marks on a skull of a T. rex, Dr. Tanner shares his theory about the creature that caused the damage to the skull with other paleontologists. He tells them that the damage was caused by a creature unknown to science. However, he says that it was not the talons that killed it; a blast of fire, precisely aimed at the head was the cause of death, as evidenced by carbon deposits discovered down both sides of the skull. Unfortunately, his colleagues aren't convinced and Tanner's academic reputation is left in tatters.
In his office Dr. Tanner studies photographs taken of a new discovery at Romania. Several human corpses, dating from the Middle Ages, were found in a cave in the Carpathian Mountains while some straying skiers were being rescued. Along with the bodies, a carcass of an unidentified animal was discovered. The Romanian authorities ask the museum to investigate the find. Most of the professors at the museum want nothing to do with the specimen, but Tanner asks if he can go on behalf of the museum. The museum agrees and Tanner prepares to travel to Romania, under one condition - if it is a hoax, they leave immediately: if it's of interest, the body is shipped back to London. Tanner, along with two associates, arrive to discover that the remains have been moved off the mountain, Tanner wonders what evidence may have been lost in the process. The three scientists enter the shed where the carcass is being housed and begin analyzing the specimen.
After initial analysis, Tanner notes that the creature has a scaly hide and a tail, suggesting a reptile, but also has wings and foot talons, characteristics of powered flight. When he finds the wings, he wonders if the creature could even really fly, as its wingspan is too small to allow flight. After further investigation, Tanner finds that the bones of the creature have a honeycomb structure, which would allow for flight, being hollow but strong. Internal scans of the creature show a huge heart, needed to pump oxygen-rich blood to the chest muscles during hard work, and two bladder-like structures. Tanner suggests that they could be gas bladders: the gas contained inside is hydrogen, which is lighter than air and would give the creature extra lift. He tells his associates that the creature has everything needed for flight but that they don't add up.
Back in the Cretaceous, two weeks after the fight with the T. rex, the mother dragon is dead, having succumbed to an infection; the starving juvenile must now teach itself how to fly, while evading the scavengers seeking to feed on his mother's body: at present, only pterosaurs, but more dangerous creatures will come. The juvenile begins to eat the only food source available; its mother's carcass. While eating, an aged male dragon arrives to feast on the mother. The juvenile, sensing danger, flees, but the older dragon, seeking fresh meat, gives chase. The juvenile flees into a forest where the adult male cannot fly. Body working overtime, the juvenile begins to make hydrogen, essential for flight, as the adult is gaining on the juvenile, nature kicks in and the juvenile regurgitates the contents of its stomach to remove excessive weight and takes to the air, narrowly escaping the adult male.
In the present, Tanner inspects inside the mouth of the creature and declares it a carnivore, but also notices molars and wonders about their purpose in a carnivore. He also notes a fleshy palate at the back of the throat and wonders if it could have been used to prevent backdraft from fire. Noting that the mouth shows no evidence of ever having been exposed to fire, he reconsiders. He theorizes that dragons breathing fire is biologically possible, explaining that the bombardier beetle can emit liquid at a temperature of 200 °C.
The prehistoric dragon, now a young adult, is preparing to fight an alpha male for territory and mates. Before it goes to fight the other adult male it eats rock rich in minerals, which is found at the heart of every dragon territory. The young adult ventures into the territory of an old alpha male. The two fight and the young male wins.
Tanner says that to create fire, they need fuel, oxygen and a source of ignition. He then realizes that he had already found fuel inside the flight bladders, hydrogen and methane, both combustible and lighter than air. He then takes samples of the crushed rocks found on the molars of the creature to discover they are rich in platinum, which can start a fire in a mixture of hydrogen and oxygen. Tanner is now convinced that his theories have been correct and the creature is a dragon. Tanner begins to wonder how dragons survived the Cretaceous–Paleogene extinction event, when other large land-dwelling creatures like the dinosaurs didn't. The narrator then explains that at the Cretaceous–Paleogene extinction event|, a meteor the size of Mount Everest smashed into the Earth, wiping out nearly all life on the planet. Sharks, coelacanths, turtles, and crocodiles all survived and all had one thing in common: they were all marine species. Tanner then remembers that crocodiles also have a false palate like the one found in their dragon, and deduces that it is an evolutionary relic passed down from a marine ancestor. The narrator continues to inform us that the land-dwelling prehistoric dragon was wiped out, but explains that the prehistoric dragon was not the only dragon species alive at the time of the K/T Event. There was also a marine dragon, a cousin of the prehistoric dragon, both descended from a common ancestor.
It is explained that the marine dragon lived in the sea and its the flight bladders became swim bladders allowing extra buoyancy, the wings became vestigial and served as fins, and the large tail became a rudder. As the land recovered from the impact of the meteor, some dragons returned to shallower waters and eventually made the transition back to land. Tanner suggests that the legends of sea serpents were actually recollections of true encounters with marine dragons. One of his associates discovers that a fossil of a false palate had been found in a bamboo forest, in China. Tanner theorizes that the marine dragon came back onto land and evolved into a new species in the bamboo forests of Asia. The dragons of Chinese mythology are low-slung, elongated, and slender; all characteristics of a body recently adapted from water, but Tanner wonders if this would have been suitable for living in a forest.
We are taken back 50,000 years to the bamboo forests of China. The age of the dinosaurs has ended, and now the mammals have since risen up to fill the void. Here we are shown the newly evolved forest dragon, adapted to its new environment. We follow the dragon as it stalks its prey, and discover that the dragon has evolved a unique adaptation; mimicry. By controlling the flow of gases out of its bladder, the dragon is able to mimic animals in distress. The vestigial wings are too small to allow flight, the dragon only able to glide small distances; but the buoyancy of the gas bladders let it tread less heavily and thus quieter when stalking prey. The dragons also use their natural fire-breathing abilities to cook their captured prey, as the fur on some of its prey is not easily digested. The dragon succeeds in dealing with several mammalian intruders to its territory, including wild pigs and tigers, but in the distance, another species watches the dragon's use of fire with inquisitive eyes, a species that will turn the dragon's own weapon on it: humans.
In the present, Tanner, after theorizing about the marine and forest dragons, begins to wonder what other dragon species may have evolved within this family of creature. Tanner's associate shows him something strange on the monitor, bone fragments. He thinks they may be ribs, but the ribs are intact. The three scientists lift the wings of the dragon to discover that it has four legs and two wings. Tanner is amazed saying, "No vertebrate that ever lived had six limbs". They check the DNA, knowing that if it is not a hoax then the limbs will show up in the DNA. The DNA test shows that the dragon has a genetic adaptation in the gene responsible for creating limbs. Tanner tells us that world mythology was correct all the time, all depictions of dragons show them to have six limbs. He cites the different depictions of dragons as evidence of a whole family of dragons existing all over the world. He dubs their carcass the mountain dragon, and wonders if this is the dragon in European folk history.
As the three scientists prepare the dragon carcass to be packed up and shipped to England, they perform one final check to see if they missed anything. They find the tip of a broken sword buried in its heart, Tanner goes to where the Romanian scientists are studying the human corpses and find the sword that the tip came from. The narrator tells us the dragons survived until the emergence of humans, who used the dragon's fire against it. These encounters between humans and dragons are recorded in folklore throughout the world. Tanner discovers that the human bodies show evidence of carbonization, showing that the bodies were burnt, but their dragon specimen never breathed fire. As the Romanian authorities come for the dragon, Tanner studies x-rays that had been taken, he sees that the ovaries of the dragon show no follicular activity, and concludes that their dragon was a baby. The three scientists travel to the cave, hoping to find a nest.
We are taken back over 500 years, to the Carpathian Mountains in the Middle Ages. Dragons have been driven to live in remote places of Europe by encroaching humans. A female mountain dragon is searching for a mate: she marks her territory with her scent. The female is near the end of her season.
The scientists arrive at the cave and find rocks that have been scorched in symmetrical lines. They scan inside the cave using echo scanning. As the female returns to her den, a male dragon arrives, having traveled to Romania from his territory in the Atlas Mountains, and the female goes to him. Instinct then takes over as the two begin their courtship ritual, where they fly to a great height then freefall together, only pulling apart at the last instant. Inside the cave, Tanner finds a nest, containing egg shell fragments and one intact egg.
Back in the 15th century we see the female dragon, using her fire to incubate the eggs inside the nest. The male returns from hunting, with no food. Instead, he brings another rock for the nest. The female, now being very protective of her nest, allows the male to enter the cave and take care of the nest. As the female takes her turn to hunt, the male enters the nest and places the rock on the nest. But instead of keeping the temperature at a high level, he lowers the temperature of the eggs in order for the eggs to develop into all females, as another male may be a rival for him; the resulting imbalance in sex ratio would have been tolerable in a healthy population but is a severe risk in a species which is now nearly extinct. The female returns from the hunt and finds the male not attending to the eggs. She quickly senses that something isn't right inside the nest. She finds out that the temperature in the nest is dangerously low and attempts to raise it again: one infant dragon has already died, but the other can still be saved. The male senses trouble and makes his escape.
The adult female has been stealing livestock from local villages in order to feed her young daughter, despite the risk of provoking the villagers. As the adult female begins to teach her daughter the secret of fire, a pair of local knights arrive to kill the dragon. They find that the young female cannot defend herself because she cannot breathe fire yet, and kill her. The adult female returns to the lair too late and finds her daughter dead. Both of the knights are soon killed by the enraged female, with one nearly managing to escape. With her daughter now dead, the adult female comes back into heat and begins trying to attract another mate. As winter comes, the female hibernates. More warriors (mercenaries paid by the locals) come to the den and catch her with her gas bladder nearly empty due to hibernation and attack her. She fights bravely, cutting down the mercenaries until only one man is left, badly wounded. As she rears above the man to crush him, he holds a spear upright. As she fatally impales herself on the spear, her toppling corpse crushes the last mercenary beneath her.
In the present, Tanner discovers a chamber. He enters it and finds the adult female. Back at the museum in England, Tanner shows the specimens to his colleagues: the legends of dragons were real, but had been twisted. The narrator tells us:
The story of life on our planet has been rewritten, by a mother and her child...reunited. The last of a legendary line. Myth made real. The myth of a sheep stealer, the reality of a mother struggling to feed her young. The myth of a vicious beast, the reality of survival...at any cost. The myth of brave knights who climb a mountain to slay a dragon, the reality of persecution and extinction. Now every dragon myth from around the world begs the same question: Were they real too? And more importantly, were these really the last dragons?
The story picks up one year later. Tanner, now Professor Tanner, is given a file by one of his colleagues. Tanner opens the file to find photographs. He looks at them, while his colleague tells him that they were taken only two months ago. Tanner runs off ecstatic, flapping his arms like wings, preparing to track down the dragon that was presumably in the photographs.