Hotland

Hotland is the fourth region the protagonist encounters in Undertale, following Waterfall. It contains locations such as Alphys's Lab, MTT Resort, and the CORE.

Features

 * Alphys's Lab, where she lives, is near the entrance of Hotland. This also holds the entrance to the True Lab.
 * Mettaton hosts four game shows/performances on the protagonist's visit to Hotland.
 * On floor 2R, Sans sells Hot Dogs to the protagonist for 25 G each.
 * He does not appear once the protagonist clears Hotland or if the protagonist killed Papyrus.
 * The protagonist can find the Art Club Room on floor 2R. So Sorry's fight occurs here.
 * The protagonist can find the Burnt Pan and Stained Apron on floors 1R and 2R, respectively. Bratty and Catty sell the Empty Gun and Cowboy Hat.
 * Muffet fights the protagonist before they reach MTT Resort. She does not fight the protagonist if they bought an item from the Spider Bake Sale on floor 3L in Hotland.
 * MTT Resort is a Mettaton-branded hotel and holds the entrance to the CORE.

Neutral Route
After defeating Undyne, the protagonist continues into Hotland. They encounter three paths. One leads to the first instance of the River Person, one to the Lab, and one to an elevator. Royal Guards initially block the elevator.

The protagonist enters the Lab and meets Alphys. Shortly after, Mettaton presents himself and engages the protagonist in a quiz show.

After completing the quiz show, Alphys upgrades the protagonist's Cell Phone to include links to two dimensional boxes, a key chain, and texting. The phone also allows the protagonist to fly using a jetpack, defuse bombs, and activate Yellow SOUL Mode.

Alphys guides the protagonist through Hotland. Along the way, they battle the two Royal Guards from earlier, solve puzzles, battle Muffet, pass through the CORE, and defeat Mettaton.

After making it to the end of Hotland, the protagonist reaches MTT Resort, where they have a chance to talk to Sans, shop at either Bratty and Catty or the MTT-Brand Burger Emporium, or continue onward towards the CORE.

In the CORE, Alphys struggles to guide the protagonist because of the CORE's changing layout. At the end of the CORE and Hotland, Mettaton fights the protagonist before they take an elevator to New Home.

True Pacifist Route
After the protagonist defeats Photoshop Flowey and befriends Papyrus and Undyne, Undyne gives them a letter to deliver to Alphys. Alphys reads the letter and goes on a date with the protagonist because she believes that they wrote it.

Then, Papyrus calls the protagonist and tells them that they should go to Alphys's lab. Inside, a note from Alphys tells the protagonist to enter the elevator if they want to know the truth. This elevator leads to the True Lab.

At the end of the True Lab, the protagonist gets on an elevator that leads to New Home.

Genocide Route
After the protagonist defeats Undyne the Undying, they enter Hotland. The sign that bears Hotland's name is not lit up and does not scroll.

In the Lab, Mettaton confronts the protagonist, but he does not force them to participate in a game show. He leaves after his dialogue. Alphys does not appear.

The Hotland elevator allows the protagonist to access MTT Resort immediately, though blue force fields block off the entire second floor of Hotland. The protagonist cannot use the elevator before Mettaton's dialogue in the Lab.

Because of the force fields, the protagonist cannot acquire the Stained Apron.

The Royal Guards encounter the protagonist earlier after the protagonist walks through floor L1. Muffet still fights the protagonist and comments that Alphys tried to evacuate her, but she refused to leave.

After defeating Muffet, the protagonist goes to MTT Resort. Alphys has evacuated everyone except Burgerpants; he tells the protagonist that Mettaton always has him work, regardless of the situation.

The protagonist then enters the CORE. None of the puzzles are activated, and they progress to Mettaton's battle. After his defeat, the protagonist rides the elevator to New Home.

Geography
Hotland is an arid region covered in reddish-orange dirt rising above the lava below. Many of the puzzles in the area involve platforms, adding to the hot atmosphere, as well as foreshadowing the technology found in the CORE.

Floor 1
Here, the protagonist will enter the Lab for the first time, and be introduced to the River Person. Monsters such as Vulkin and Tsunderplane are first encountered on this floor, but only after exiting through the right side of the Lab. This area mainly serves to introduce the protagonist to the steam puzzles and conveyor belts that are abundant through Hotland.

Room 1
Here, the protagonist can find a small room with a water cooler. When checked, the water cooler gives the protagonist a cup of water. Dumping out the water causes a small puddle to appear next to the water cooler, which gradually gets larger the more water that is spilled into it. Attempting to take the water out of the room will cause it to evaporate. The second time the protagonist enters this room, the Clam Guy NPC will be here. He will tell the protagonist that he came to Hotland to get a drink from the water cooler. If approached with a cup of water, he will ask if the protagonist plans to look sophisticated by carrying the water around, then inform them it is not working.

If the protagonist came here while pursued by Undyne, she will collapse here, and block the path back to Waterfall. If the protagonist pours water on her head, she will get up and walk back to Waterfall. Clam Guy will not appear in this room when pursued by Undyne.

Room 2
This area is a four-way crossroads that the protagonist enters from the east. The north path is initially blocked by the Royal Guards, who claim to be blocking the way for Undyne. After fighting the protagonist on floor 2L, the path becomes unblocked. The south path leads to the River Person, who will offer to ferry the protagonist back to Snowdin and Waterfall. The east path leads to the Lab. In the middle of all four paths, a SAVE Point is visible.

Lab
When the protagonist first enters the lab, it is dark, and any items checked are reported as too dark to see. Proceeding farther into the Lab will cause Alphys to walk out of the bathroom, and turn on the lights. Upon noticing the protagonist, they will exclaim excitement at their arrival, and fret that she did not have enough time to get ready. After, she informs that protagonist that she has been watching their progress after they left the Ruins, and that she originally planned to stop them. However, she decided to help them instead after growing attached to the protagonist.

She will then explain that she built an entertainment robot years ago named Mettaton. Alphys then explains that she outfitted Mettaton with anti-human defense capabilities, and she attempted to disarm the program once she saw the protagonist coming. Unfortunately, she failed, and it turned Mettaton into an unstoppable robot with a "thirst for human blood." Soon after she finishes explaining, Mettaton attacks the protagonist, and pits them against his "Quiz Show".

After the battle, Mettaton will depart, and the protagonist may move forward. If the protagonist attempts to leave the lab, however, Alphys will run to them, and give the protagonist her phone number. After seeing how old the protagonist's phone is, she will upgrade it to receive texts, and allow the protagonist to access two more storage boxes called "Dimensional Box A and B." Afterward, Alphys will depart into the bathroom, leaving the protagonist to explore the rest of the lab and move on.

The first floor of the lab has two entrances, one to the far left of the lab, and one to the far right. Near the left door is a large monitor that displays the protagonist's face. Checking it causes them to remark "It's you...?". To the right of the monitor is a messy desk, complete with several stacks of paper, a plastic anime figurine, and a large computer. Nearby is a fridge where the protagonist may receive one cup of Instant Noodles.

Next to the fridge is a large bag of dog food. To the left and right doors are two elevators. The one at the left door leads downward, while the one near the right door leads up. Taking the elevator will lead the protagonist to the upper floor of the Lab. To the left of the elevator, a conveyor belt can take the protagonist through the rest of the upper floor with ease.

On the upper floor, many bookcases containing anime comics and videos are visible. To the left of the bookcase is a large machine oozing pink goop, with something green being stuffed down the top. Nearby is a lab table with several books and tools. Above the workbench is a poster of an anime character. Beyond that is a dresser with some dirty lab coats and a single clean dress. Nearby, a "bed" is found.

When checked, it says that when not in use, the bed folds into an "extremely easy to draw box." Right beside the leftmost elevator, a poster for a show by Mettaton is hanging on the wall.

Room 3
After exiting the right side of the lab, Alphys will begin texting the protagonist with frequent updates of her status on Undernet. Going up will take the protagonist to a large system of conveyor belts going forward and backward. Shoots of flame also burst from nearby pipes, adding to the scenery. After reaching the end of the conveyor belts, the protagonist comes into view of several small islands surrounded by boiling lava. Most of these islands hold steam vents.

Stepping on these will cause the protagonist to jump from the steam vent in the appropriate direction that the vent is facing. Here the protagonist can go two ways up or down. The upper path leads onward, while the lower path will show the protagonist to the Burnt Pan.

Upon taking the lower path, a steam vent rapidly changing from left to right appears. Next to it are two islands with conveyor belts. On the left island, the protagonist can recover the Burnt Pan. The right island has nothing, however. The protagonist must get on the steam vent immediately after it switches to the left to get the pan.

Regardless of what island the protagonist lands on, conveyor belts on each side of the island will take the protagonist back to the steam vent.

Room 4
Upon entering the north path past the steam vents, the protagonist comes to another path that veers to the right. Soon after stepping into the room, Alphys will call the protagonist, and inform them of the orange and blue lasers nearby. She reports that you must be moving to avoid being hit by the orange lasers, and stay still to get past the blue lasers. Afterward, she will hang up. In the path, several rows of orange and blue lasers, which the protagonist must evade to make it safely through the path. At the end of the laser field, the path veers upward in Room 5.

Room 5
In room 5, the protagonist comes across the Reactivated Door puzzle. On the left and right, the protagonist must solve two puzzles to move forward. To reach these puzzles, the protagonist must step on a steam vent that rotates clockwise between the north, south, east, and west. Upon entering the room, Alphys will inform the protagonist that the right path is easier, and they should try that puzzle first. On the right path, two NPCs are found sitting on the ground.

The left one tells the protagonist that they managed to catch Mettaton's show on his phone, and remarks about how realistic the human looked. The right NPC explains that they cannot get to work, as puzzles have activated, impeding their progress. Inside the puzzle room, the Disembodied Fox Head explains that his co-workers will not help him solve the puzzle, and questions if they even want to go to work today. After completing the puzzle, he remarks surprise when checked, and concludes that the protagonist must be a "total nerd" to solve the puzzle.

The left puzzle is blocked by a blue laser, which impedes the protagonist's progress. Soon after entering the room, Alphys calls the protagonist, and turns off the blue laser, allowing further progress. Like the right puzzle, two NPCs wait outside the door, named Fuku Fire and Skateboard Girl. Fuku Fire exclaims relief about the laser going down, then questions what she'll do. After thinking, she decides to continue standing where they are. When checked, the Skateboard Girl is happy about the laser blocking them from leaving, as it gives them an excuse to skip school.

After solving both puzzles, a door to the north will open, letting the protagonist proceed. Before reaching the door, Alphys will once again call the protagonist, and begin to explain the puzzles. Once the protagonist tells her that they have already completed the puzzles, however, she becomes embarrassed and quickly hangs up.

Room 6 and Mettaton's Cooking Show
After solving the Reactivated Door Puzzle and leaving Room 5 through the now-open doorway, the protagonist is greeted with a small pathway, and a steam vent pointing to the left. Walking on the steam vent will project the protagonist trough three other steam vents, which eventually lead the protagonist to a lime-shaded floor with several large dots. The protagonist may not turn back once they reach this area. Upon going to the right, the protagonist must face Mettaton again in his Cooking Show. Afterward, the protagonist may continue to the right.

Here, A large view of the CORE can be seen. Shortly after, Alphys will call the protagonist and tell them not to worry. At the end of the passageway, an elevator is visible, which will take the protagonist to Floor 2.

Floor 2
Here, the protagonist must face puzzles such as the Conveyor Belt Puzzle and the Vent Puzzle. This is the first floor the protagonist can encounter Pyrope. At the end of floor 2, the Royal Guards fight the protagonist as mini-bosses. Sans will also sell Hot Dogs near the beginning of this floor, provided that Papyrus has not been killed, or Hotland has not been cleared.

Room 1
After exiting the elevator, Heats Flamesman and a path leading off to the left are visible. Heats Flamesman tells the protagonist his name when talked to, then asks them to remember it.

The left path leads to Sans, who is selling Hot Dogs for 25g each. No monsters may be battled in this room. Nearby are two NPCs, both with Hot Dogs of their own. One of them, called Hot Dog Harpy, will remark on the snow atop Sans Hot Dog Shack, then decides he must be too lazy to clean it. The other NPC, a Vulkin with a Hot Dog, will exclaim "Toasty Buns!" when talked to. Next to the Hot Dog Shack, a path leads west, which takes the protagonist to the next section of Hotland.

Room 2
This room has three visible passages, along with one secret passage directly north of the south path. The path east leads the protagonist back to Sans's Hot Dog stand. The south path will award the protagonist with the Stained Apron, an armor item that slowly heals the protagonist. The west path leads onward to the Conveyor Belt Puzzle. The north path, however, leads to a special room called the Art Club Room.

This path is invisible, and can only be seen when the protagonist walks on it. Here, the protagonist may fight So Sorry if the game is launched while the player's clock is set to October 10th, at 8:00 PM. This can only be done if Hotland is cleared.

Room 3
Here, the protagonist must solve the Conveyor Belt Puzzle to move forward. Upon entering the room, Alphys will call the protagonist to explain the puzzle to them. Upon completing the puzzle, a path to the left becomes accessible, allowing further progress. Here, the protagonist must solve The Vent Puzzle. Shortly after approaching the puzzle, Alphys will yet again call the protagonist, and tell them that she has to go to the bathroom. Afterward, she will not call the protagonist until after the Royal Guards have been defeated.

Mettaton's News Report and Room 4
After completing the puzzles, the protagonist will come across a SAVE Point. Nearby is a mousehole, and a safe atop a small table. Checking the table will make the protagonist remark on how the cheese inside has been melted by the laser safe, causing it to become stuck to the table. After the SAVE Point, the Royal Guards will approach the protagonist, and warn them of a Human in a striped shirt roaming Hotland.

After realizing the protagonist is said human, they attack. After the battle, the protagonist comes across another dark room. Here, the protagonist faces Mettaton's News Report. Afterward, the protagonist may continue forward toward elevator L3 (and another scenic view of the CORE). This elevator leads to the final stretch of Hotland: Floor 3.

Floor 3
This is the last stretch of Hotland before the protagonist reaches the MTT Resort. Here, the protagonist must face another Reactivated Door Puzzle and Mettaton's Multicolor Tile Puzzle. The protagonist must also fight Muffet here.

Room 1
After leaving the elevator, a path to the east will lead the protagonist to Muffet's Spider Bake Sale. Here, the protagonist can buy a Spider Donut and Spider Cider for 9999g each. Besides the bake sale, a single NPC lies in this room, holding a spider donut. When talked to, he claims he did not want to buy a donut, but Muffet scared him into buying a donut and spending all his money.

Going forward takes the protagonist to the second Reactivated Door Puzzle. After beating this puzzle, a door to the far right will open up, allowing passage. After beating the puzzle directly north, two NPCs, called Diamond Boys will appear. They talk about their favorites moments on Mettaton's show.

The lower door puzzle is blocked by lasers, which the protagonist must dodge. After beating this puzzle, Alphys will call the protagonist, and ask if they want to watch anime with her. Saying yes will cause Alphys to talk a great length about her favorite anime, "Mew Mew Kissy Cutie." Saying no will simply cause Alphys to hang up.

Muffet's Lair and "Undertale, the Musical"
After beating the Reactivated Door Puzzle, the protagonist comes across a SAVE Point and a doorway to Muffet's Lair. Upon walking through, Muffet will trap the protagonist, intent on killing them. See Muffet/In Battle for more info on this fight. The path out of Muffet's Lair leads to a small stage, where Mettaton begins "Undertale, the Musical" and the Multicolored Tile Puzzle. After, the protagonist comes across a small room, with a four-way crossroads. Nearby, the Nice Cream Guy will sell the protagonist Nice Cream for 15g each.

The south and west paths lead back to the Multicolored Tile Puzzle and the Undertale Musical, respectively. The east path leads to elevator 3R, where Heats Flamesman waits. He asks the protagonist if they remembered their name. Regardless if the protagonist says no or yes, Heats Flamesman becomes shocked, and questions how he could be so easily defeated. The north path leads to the MTT Resort.

Trivia

 * If the protagonist pours out all the water in the water cooler while Undyne is passed out, then checks the now-empty water cooler, the check will say "Sadistically, you have poured out all the water right in front of Undyne's eyes."
 * For the requirements of the Genocide Route, Hotland and the CORE are counted as a single region.
 * On the shooting puzzles, occasionally the 'Restart...' text will read 'Restaurant...' instead.
 * The design and the fact that this area contains machinery and lava might be a reference to the Land of Heat and Clockwork from Homestuck. Interestingly enough, Another Medium was originally a remix of the Homestuck song, "Doctor," titled "Patient."