- The Screaming Death returns, now sinking islands.
- Hiccup introduces Air Mail/Terror Mail
- The Dragon Riders stop the Screaming Death from sinking Dragon Island.
The scene starts with two wild Deadly Nadders resting after a long day's flight, but are suddenly interrupted when they get tagged with yellow paint. Hiccup and Astrid are actually tagging them so they know which dragons belong to a corresponding island; the dragons who get tagged yellow lives on Sorrow Island. Astrid is able to tag a few Deadly Nadders and challenges Hiccup to join in. Astrid misses one, Hiccup suddenly joins in blazing speed and in seconds catches up to the missed Deadly Nadder, Hiccup corners in front of the Deadly Nadder and transforms his shield to a crossbow and uses the paint as his ammo, fires and finally tags the Deadly Nadder in a clean shot. Astrid then admittedly complements Hiccup's complex shield. Hiccup heads out to see the twins' progress at Crescent Island, while Astrid sarcastically ensures that they're doing fine.
On Crescent Island, the twins both spot an unmarked wild Gronckle enjoying it's meal of rocks. Tuffnut aims and throws a pouch of purple paint at the Gronckle, but the dragon flew away and he hits Ruffnut instead, who was about to fire too. Tuffnut laughs and jokes about Ruffnut instead of apologizing. Tuffnut eventually apologizes, sarcastically, and jokes about Ruffnut even more. Ruffnut, furious, throws her paint at Tuffnut and the two start a fight by throwing most of their paints at each other. Hiccup suddenly calls them, and the two suddenly throws it at Hiccup, who luckily manages to dodge them both. Hiccup reminds them that they're suppose to be tagging dragons, but the twins' blame Hiccup and Hiccup asks how did they figure that out, Ruffnut states obviously that Hiccup armed them with paint and knew that they were just gonna make a fool out of themselves. Tuffnut asks how many do they need to tag anyways, Hiccup answers as many as they can so they can keep track of the dragons who live in their respective habitat and where they may migrate to. Ruffnut pretends to be amazed but doesn't know what words to say, Hiccup asks if they find it fascinating, but Tuffnut asks what's the opposite of it. Astrid asks Hiccup if it's one color per island, Hiccup asks why, Astrid says she sees two differently tagged dragons present on the island, Astrid asks if they were using the wrong ones and the twins' are not responsible for. Hiccup suggests that he informs Fishlegs due to the fact that it was his idea.
Astrid states that they're too far to fly all the way back to Berk, but Hiccup says they don't need to and starts writing on a piece of paper. Ruffnut doesn't know what he means, Tuffnut says it might be the 'magic paper' they were searching for so long. Hiccup says that it's not 'magic paper', Hiccup and Fishlegs have been testing their new idea of doing 'Air Mail'. The twins laugh at the name. Astrid thinks that it's not a suitable idea to send a Terrible Terror to fly straight to Berk, however Hiccup believes it will and justifies it by saying that Terrors are highly territorial and it's a natural instinct for their species to return to wherever they belong to. Astrid asks how will they know if he makes it, Hiccup answers that they'll know when they see Fishlegs and Snotlout at Dragon Island. Astrid still doesn't believes this, stating that she'll kiss Snotlout on the lips if that happens.
Unfortunately, it did happen; Fishlegs is seen at Dragon Island with Snotlout and the sent Terrible Terror, Snotlout fast asleep near a rock. The two arrive, Hiccup, as expected, points out Fishlegs and Snotlout both being on Dragon Island, and also mentions that Astrid was just talking about them. Hiccup mocks Astrid, making kissing noises at her. Astrid silently warns Hiccup that if he mentions what she just said earlier, it 'will be his last words'. Hiccup then swallows in fear. Fishlegs is glad that air mail works and asks what's the situation. Hiccup tells Fishlegs that they've been seeing different color tags on the dragons back at Crescent Island. Snotlout interrupts and is not satisfied with their situation because he was doing something important, which is actually just sleeping, but he refers to it as his 'beauty rest'. Furthermore, it's not making sense that green color tagged dragons should be on Crescent Island because they're supposed to be marked purple. Astrid asks what there were green tagged dragons doing there. Fishlegs answers that first of all the actual name for the color is pistachio, and that they belong to Tall Tree Island. The gang becomes suspicious and suggests they head out to Tall Tree Island. As they fly, Snotlout ditches the mission and heads back to Berk. They arrive at their destination, but are unable to see the island. Astrid tells them that maybe they were off course, but Fishlegs is sure that they don't do 'off course'. Fishlegs grabs his map and tells them that they are now in its location but finds nothing except dead sea. The three gets suspicious, knowing that an island can't just disappear instantly. Suggestions given for the disappearance might be earthquakes or volcanoes, but Fishlegs' third suggestion was that it was the Wrath of Thor and Odin. Hiccup and Astrid stand quiet after hearing that. The three then see fleeing wild dragons headed straight past them, Astrid identifies them that they have orange tags or Bur Apricot by Fishlegs. The orange mark dragons belong to Sunstone Island, Fishlegs recall its great landscapes such as its pristine beaches and fine variable of rocks and minerals for Meatlug.
Hiccup suggests that they go to Sunstone Island, as they arrive the trio sees that Sunstone Island has appeared to have 'sunk', they even struggle to get their dragons to get into position except for Fishlegs. Fishlegs recaps one island missing and one island sunk, Fishlegs questions to where do dragons migrate if their respective habitats are gone. Hiccup states that dragons live in specific islands for specific reasons such as the food they eat and where they nest, if their homes continues to disappear it could endanger their entire species. Hiccup proposed that they try and figure out what's going on and head back to Dragon Island, if it's still there. As the three head back, a dragon shadow figure flies overhead the sunken island.
On Dragon Island, many different species of wild Dragons now seek refuge, Astrid tells Fishlegs to check their colors, Fishlegs sees pistachio marks, Burn Apricot marks, Astrid then sees a new color which is red, but Fishlegs technically calls it Vermilion. Hiccup identifies the colors belong to three different islands, the instant disappearances of the islands form a line, and endangers the other nearby islands: Boarhead Island and Thor Rock Island. Hiccup and Toothless wants to head out to check the islands, Astrid wants to come with Hiccup because it might get dangerous, Hiccup asks why, Astrid states that Islands are disappearing mysteriously, and dragons fleeing in terror and points out why it could dangerous. Hiccup lets Astrid to come with him and tells Fishlegs to stay on Dragon Island and look for anymore new dragons.
Hiccup and Astrid arrive only to see Boarhead Island gone too. The two then fly otherwise to Thor Rock Island, they see its devastated remains and Astrid begins to accept Fishlegs' theory about the wrath of the Norse gods. Hiccup and Toothless lands on the remains of the island to get a closer look. As they land, they see a huge marking that seems familiar but somehow different, Astrid asks how, Hiccup responds that they're bigger. Suddenly a loud roar is heard and rocks begin to tumble, and a huge dragon comes out of the huge hole and is actually the full-grown Screaming Death. The Screaming Death has grown bigger and disorients Toothless and Stormfly with its scream, the Screaming Death burrows underground and Hiccup figured out why the islands are disappearing: the dragon has been destroying all islands by tunneling underground and making the island collapse in on itself. Hiccup suggests they get a closer look, while Asrid is reluctant but Hiccup says that she did want dangerous. The Screaming Death suddenly closes in on Hiccup and Toothless and they fly away from the dragon. The Screaming Death, in pursuit of Hiccup, fires several blasts at them and destroys anything that's in his way. Astrid distracts the dragon by throwing some 'pistachio' paint tags at the dragon's eyes. While the dragon's vision is blurred, Hiccup and Astrid attack the Screaming Death and flee from the battle.
The two return to Dragon Island, where Fishlegs tells them that there are now periwinkle-blue dragon marked dragons from Boarhead Island and eggshell-white marked dragons from Thor Rock Island. Fishlegs asks what happened to the islands and Hiccup answers that its the Screaming Death. Hiccup marks the destroyed islands and says that the Screaming Death will continue to destroy any island that's in its path. Fishlegs points out that it is headed straight to Dragon Island,but Hiccup says that it's even worse than that. It's headed straight to Berk after it destroys all the other islands in its path. Fishlegs suggest that they warn Stoick, but Hiccup denies it and says that they make their stand on Dragon Island, because there's no other land between there and Berk. Astrid is afraid that they're not going to be able to defend the Island just themselves. Hiccup calls for reinforcements which is Snotlout and the twins, via air mail.
At Berk, the twins are playing hide and seek. Tuffnut asks Barf and Belch where Ruffnut is, but they are too lazy to answer. Ruffnut reveals her position that she's above Tuffnut and spills purple paint near him. Ruffnut makes a run for it but she is grab by the foot and trips. Tuffnut laughs at her and the two quickly wrestle each other, the two suddenly see the sent Terrible Terror by Hiccup and wonders why is it staring at them and what it wants. They run and hide from the Terrible Terror, but he remains stubborn and follows them. Back on Dragon Island, Hiccup keeps on a lookout for any sign of the Screaming Death. He is then informed by Fishlegs and Astrid that yellow marked dragons, who belong on Sorrow Island, are now recently seen seeking refuge on Dragon Island. The Screaming Death is now only one island away. It looks like reinforcements are not coming and Hiccup suggests that they set up a defense on their own on Dragon Island. Astrid suggests that they head home to Berk but Hiccup denies that plan because if Dragon Island disappears all of the wild dragons will overwhelm Berk. Suddenly a loud roar is heard that warns the three that the Screaming Death is getting closer by the minute. Hiccup and Toothless volunteers to distract the Screaming Death and buy some time for Snotlout and the Twins to come, he denies Astrid's permission to join him and assigns her to stay behind if the Screaming Death goes pass him.
Back on Berk, The twins pretend to be statues in order for them to be unnoticed by the Terrible Terror, Snotlout asks why are they pretending to be statues, the twins tell Snotlout to be quiet and tells him to pretend that they are not here, Snotlout questions this and looks behind him only to see mail has arrived, he grabs the note from the Terror and Snotlout still points the twins as muttonheads, but they prefer it to be as Statues of Muttonheads. Back on Dragon Island the Screaming Death is seen heading its way on full speed but gets distracted when it gets ambushed by Hiccup and Toothless. Hiccup tries to draw more attention to the Screaming Death by making it follow Hiccup's shield again. The two chases each other for a brief moment when the Screaming Death knows that its being distracted and continues its way to Dragon Island, Hiccup tries to draw its attention to him again but he remains stubborn, he and Toothless gets whacked by its tail they manage to regain control and tries to figure out another diversion due to the fact it's getting bigger and smarter. On Dragon island, Astrid still doesn't believe to rely on their idea of Air Mail, but Fishlegs says that they can because Terrors' are territorial, suddenly Fishlegs come up with an idea, he calls Astrid a genius and even considers kissing her in the lips, Astrid goes angry and states that no one is going to kiss her in the lips ever.
The two see the Screaming Death and Toothless slowly making its way to Dragon Island, Fishlegs tells Astrid to cover Hiccup's back while he go and prepares his plan, Astrid asks where is he going and Fishlegs tells Astrid to just trust him on this. Astrid arrives and joins in and harass the dragon, Hiccup suddenly sees Fishlegs and warns him that he needs backup, Fishlegs idea was actually assembling the other wild Gronckle dragons to join in against the Screaming Death to defend their new home, the Gronckles fire multiple shots around the Screaming Death and able to get its attention. Astrid how did Fishlegs manage to do it, Hiccup answers that Gronckles are territorial dragons too. The Screaming Death, having enough, dives and burrows underground. Hiccup orders Astrid and Fishlegs to gather as many wild dragons as quickly as possible while he tries to keep the dragon on land. As they enter its tunnels, they see the underground terrain collapsing and water levels rising underground. The Screaming Death suprises Hiccup and Toothless and tries to escape in the dark carvens and tunnels while the Screaming Death is in pursuit, luckily Toothless has the ability to locate where they are going using echolocation. They find their exit blocked by collapsed boulders Toothless manages to find another route upward, and the Screaming Death bashes his head against the blocked route. Hiccup and Toothless finally escapes and finally sees Snotlout and the Twins arrive, they are shocked to see the Screaming Death bigger but the Twins still think it's awesome. Astrid arrives with a herd of wild Deadly Nadders joining in to defend their new homes too. The Riders and all the wild dragons attacks the Screaming Death in multiple fronts and the Screaming Death is unable to counterattack and flies away from the battle, finally ending its appetite for destruction. However, due to the Screaming Death's mass tunneling underground, the island begins to sink and collapse. Fishlegs quickly comes up with an idea and gathers all the Gronckles to spew molten lava as many times as possible to create a new terrain that quickly dries up solid. The island finally stops sinking and collapsing, and the island is now stabilized. Hiccup congratulates Fishlegs as the hero on this day.
Hours later on Berk, Snotlout gloat about their victory a while ago that only involves only him and not the other wild dragons, but Fishlegs is just happy that he doesn't want to see the Screaming Death again because it gives Meatlug gas. Astrid asks Hiccup if he got any info about the Screaming Death, the good news is that the Screaming Death is revealed only to to hatch every 100 years, then they all ask Hiccup what's the bad news, Tuffnut says that it's going to be 'the end of the world', their theory is close to Hiccup's answer despite he was only kidding. The bad news that it's still out there and may one day seek its revenge again to the Isle of Berk.
- Hiccup and Fishlegs come up with the idea for air mail by using Terrible Terrors as messengers. The one they used in this episode is most likely Sharpshot.
- The idea of tagging the dragons with different colors to check on them is an actual technique scientists use to track various animal species.
- When Snotlout calls the twins idiots for the second time, his armbands are gone.
- Astrid said if the others get Hiccup's letter, she'll kiss Snotlout on the lips, which she refuses to do later in the episode as well as threatening Hiccup, though it is possible she did not want to do it with Snotlout or she is more comfortable with kissing Hiccup.
- Although this episode is called Appetite for Destruction, the Screaming Death doesn't actually eat the islands, it sinks them by tunneling under the islands, although it may actually eat part of the rock it tunnels through.
- Hiccup says he learned that the Screaming Death hatches once every hundred years, however, there is no record of it in the Book of Dragons. Although it is quite possible that Hiccup found that information in one of Bork the Bold's notes. Since Bork the Bold lived over a century ago, he might have encountered a Screaming Death before.
- Near the climax, Astrid said to Hiccup and Fishlegs that no one will ever kiss her on the lips, but she has kissed Hiccup on the lips three times before; so, she might have meant anyone other than Hiccup.
- It is also shown frequently that Astrid likes to be in Hiccup's company over the other teens regardless of the dangers that could be present.
- The Screaming Death has grown larger since the episode Tunnel Vision.
- Ruffnut and Tuffnut state that they have been looking for magic paper when Hiccup is writing the Terror Mail.
- Jay Baruchel as Hiccup Horrendous Haddock III
- America Ferrera as Astrid Hofferson
- Christopher Mintz-Plasse as Fishlegs Ingerman
- Andree Vermeulen as Ruffnut Thorston
- T.J. Miller as Tuffnut Thorston
- Zack Pearlman as Snotlout Jorgenson