Dragonvine is the second post-How to Train Your Dragon 2 graphic novel. It continues the story of The Serpent's Heir. It was exclusively available at comic retailers on August 22, 2018, and then officially published on September 4, 2018.
This second standalone graphic novel based on the film series is a new adventure that takes place shortly after the events in How to Train Your Dragon 2 during the period in which Hiccup is desperately trying to fill his father’s role as the chief of Berk. Created with the help of the film’s writer, director, and producer, Dean DeBlois, it bridges the gap between the second and third films.
|“||Hiccup, Toothless, and the rest of the dragon riders encounter two deadly yet mysteriously linked threats: One is an island consumed by Dragonvine, an uncontrollable force of nature that’s poisonous to humans and deadly to dragons. The other is an all-new, all-terrifying dragon species–the web-spitting Silkspanners!||”|
|“|| Trapped by the Silkspanners, a mysterious new species of web-spitting dragons, Hiccup and Toothless must lead their friends in a fight for freedom. But escaping the Silkspanners is just the beginning. When our heroes encounter a group of villagers in peril from the deadly Dragonvine plants, they must put themselves at risk to help their new friends.|
But are the villagers friends? Or is the Dragonvine part of an evil plan? And how do the Silkspanners fit into everything?
|— Back cover|
After Toothless collapses the cave entrance, all the Dragon Riders and Toothless are trapped in a cave. So, they start sharing stories about Stoick. After a bit, Hiccup coats everyone's weapons in Monstrous Nightmare Gel and set them aflame, so they would be like the Dragon Blade.
Toothless then blows open the cave entrance, and all the Dragon Riders rush out. After the Dragon Riders have a talk in the forest about the newly named Silkspanners, Astrid frees Stormfly and then sets out to free the other dragons (excluding Toothless).
Hiccup then removes his armor, leaving him wearing only a green shirt and brown jacket. Toothless then throws Hiccup the shield and Hiccup uses it to launch Inferno using the built-in crossbow. Inferno explodes just by Toothless and the Silkspanners, freeing Toothless from the webs he was trapped in. All the other dragons then breath fire onto Toothless, completely freeing him.
The Silkspanners then run off, but not before webbing up Snotlout's mouth, and also allowing Hiccup to grab a Dragon Hunter arrow out from one of the Silkspanner's hides.
Fishlegs then tries the use the Dragon Cry to find out any info on the Silkspanners, only to come up with nothing. The Riders then come up with a plan. Snotlout, Valka, and Fishlegs all go back to Berk while Hiccup, Astrid, Eret and the Twins try to find out where the Dragon Hunter arrow had come from.
The Riders searching for the source of the arrow find an island covered in dragonvine, which is poisonous to humans and deadly to dragons. Hiccup and Toothless then save a couple of villagers from the dragonvine.
They then meet Bayana, who tells them that his people have moved from island to island trying to find safety after Drago Bludvist burned their original village to the ground when he found out that they were all farmers instead of warriors for his army. They eventually settle on the Silkspanners' island and are forced to drive the dragons away.
Realizing the dangers of the dragonvine could pose if they infest the entire archipelago, the Dragon Riders divide themselves into two teams: Hiccup, Astrid and Gobber will head out to find the Silkspanners to see if they are connected to the dragonvine, while Eret and the Twins will help Bayana's Tribe from being overwhelmed by the dragonvine.
Back on Berk, Fishlegs and Valka are consulting with Skulder the Archaeologist about the Silkspanners while Snotlout tried to overcome his fear with the help of Gothi. As Valka comments on how Gothi deeply disturbs her, Fishlegs and Skulder come across something in the Dragon Cry.
In the open sea, Hiccup and Astrid are having difficulties in tracking down the Silkspanners, until Gobber gave Hiccup the idea that the Silkspanners need a really strong wind gust to help them in gliding from island to island. However, they are unaware of a small, yet fast-growing dragonvine that appears within Toothless' saddle.
Eret and the Twins traverse through a dragonvine forest, with the former confident that the dragonvine has a root. Not long after, they are unexpectedly joined by Bayana.
Hiccup and his team eventually comes across an island that has become a nest of newly-hatched Silkspanners and their mother. Unbeknownst to them, the dragonvine inside Toothless' saddle is continuing to grow.
As Eret and his team continues to destroy more dragonvine, he comes across some heavy-duty farming equipment that Bayana is somehow oblivious of. Bayana notes that whoever left the equipment must have not abandoned the field fast enough, which is proven when he caught a glimpse of several bodies that have been strangled by dragonvine above him. The dragonvine continue to close in on the group, and Skullcrusher, Barf and Belch have already exhausted their firepower. Knowing that they cannot always rely on their dragons, the group resort in using bladed weapons in hacking any vine that comes too close.
Hiccup's team are forced to ward off the Silkspanner family from attacking, until the dragonvine in Toothless' saddle has grown large enough to lift and strangle the Night Fury.
Eret's team are slowly overrun by dragonvine. Eret then starts to feel air coming out of a hole in the ground. He then has the idea of filling the hole with Barf's gas and have Bayana fire a flaming arrow into it, creating a massive underground hole that leads to the root of the dragonvine: the skeleton of a Titan Wing Snaptrapper.
Toothless is succumbing to the dragonvine's toxin as the Riders attempt to burn it down. At the same time, the baby Silkspanners are becoming more riled up than before. Hiccup is slowly reduced to tears when he realizes that Toothless is dying, for he is not ready to say goodbye to his best friend. The baby Silkspanners then start to swarm on Toothless as Hiccup tries to force them off him. But before he could, Fishlegs and Valka arrive on Cloudjumper and they reveal that the Silkspanners feed on dragonvine, allowing them to free and cure Toothless.
As the twins stare at the skeleton, they start to believe that when the Titan Wing Snaptrapper came to the cave to die, its blood and pus fertilized a normal weed and mutated it into dragonvine. Bayana tries to find a way out as Eret come across a cave filled with bulbs of dragonvine, where he realize that Bayana's tribe have been harvesting the plant as weapons of war. The Riders and their dragons are eventually captured and imprisoned to a dragonvine-filled pit, which causes Bayana to reconsider about his tribe's agenda. When the Eret's team are about to be overwhelmed by the dragonvine, Toothless blast their cage open and have the baby Silkspanners lift them out.
With the two teams reunited, Fishlegs note that the Silkspanners have evolved to become immune and feed on the dragonvine so that the plant will not infest other islands. Hiccup then confronts Bayana's tribe about the dragonvine they have placed on Toothless' saddle and give them a choice: move from island to island and seek revenge, or end the cycle of aggression by coexisting with the Silkspanners. Hiccup even offers to teach them on training the Silkspanners, but Bayana said he can fill that role as evidenced by the two juvenile Silkspanners that have bonded with him.
Bayana's tribe decides to live alongside the Silkspanners and burn the dragonvine that they are harvesting. Hiccup then tells Astrid about how his father loved Berk so much that it is more than just a place, it is a people. He settles in for the plan of opening Berk's borders to any human or dragon in need.
As a storm closes in on the island, a single bulb of dragonvine is seen drifting out to the open sea.
- Hiccup Horrendous Haddock III
- Astrid Hofferson
- Snotlout Jorgenson
- Fishlegs Ingerman
- Tuffnut Thorston
- Ruffnut Thorston
- Eret, Son of Eret
- Gobber the Belch
- Skulder the Archaeologist
- Stoick the Vast (mentioned)
- Oswald the Agreeable (mentioned)
- Drago Bludvist (mentioned)
- Barf and Belch
- Bayana's Silkspanners
- Muddie (mentioned)
- Night Fury
- Deadly Nadder
- Monstrous Nightmare
- Hideous Zippleback
- Snaptrapper (skeleton)
- Mudraker (mentioned)
- In the story Astrid tells while being trapped in the cave, Hiccup and Toothless are depicted to have left to Itchy Armpit at sunset, with Stoick standing on a nearby cliff and watching as they leave. This is however directly contradicted by the movie, as Hiccup and Toothless left early in the morning, largely unbeknownst to the other Berkians, who were all playing Dragon Racing at the time.
- This graphic novel introduces three elements into the main canon, only existing in the game School of Dragons, specifically: the Dragon Cry, Skulder the Archaeologist, and Muddie the Mudraker, even if the third one is only mentioned.