
Fire elements Bernie and Cinder Lumen immigrate to Element City, where they encounter xenophobia from other elements and struggle to find a home.
They had a daughter, Ember, and eventually set up a department store called Fireplace, setting up Blue Fire which represented their heritage and traditions and attracted many fire element customers over time.
Bernie intends to give the store to Ember when he retires, but first he must control his burning anger.
When Bernie allows Ember to run his own store, he becomes overwhelmed by customers and rushes to the basement.
His fiery explosion broke the water pipes, flooded the basement and called out to Wade Ripple, the water element and the city inspector.
Wade records the damaged plumbing and reluctantly goes to City Hall to send a report of the breach to his air element employer, Gale Cumulus, who is about to shut down the Fireplace. Ember chased Wade but it was too late.
Pitying Ember, Wade takes her to Typhoon Stadium to convince Gale to reconsider closing her father's shop.
When Wade mentions that he is investigating repeated flooding before ending up at the Fireplace, Gale gives the two a strict deadline to find the source.
If they are able to close the leak, then the breach will be forgiven. While searching for the source of the leak in the canal, Wade suspects that Ember's anger came from him trying to tell himself something he wasn't ready to accept, but Ember denies it.
They then found a hole in the dam that allowed wave runoff from the ship to flood the city's plumbing, so they sealed the hole with sandbags. Meanwhile, Bernie copes with water leaks throughout the Fireplace.
Wade and Ember spend time together in the city and learn more about each other.
Meanwhile, Cinder suspects Ember is dating someone and follows her. Ember visits Wade's family in a luxury apartment, where she uses her fire to fix a broken glass jug, impressing Brook, Wade's mother, who recommends her for a glass-making internship.
Ember also played a crying game with Wade, where she managed to make him cry when she admitted that she had feelings for him.
Gale then called Wade and gave his approval of the Bucket glass seal, thus saving the Fireplace from closing. Ember then realizes that she does not want to take over the store.
Bernie announces his intention to retire and hands the Fireplace to Ember. He told his daughter how, when leaving his homeland, he bowed to his father but his father refused to bow back.
Wade takes Bucket to Garden Central Station to see Vivisteria flowers, which he rejected as a child. With the station now flooded, Gale gives Bucket an air bubble for safety while Wade pushes it underwater through the station.
Afterwards, Wade and Ember find out that they can touch each other without hurting each other and share a romantic dance, but Ember reminds herself of her duty at the Fireplace and her family's prejudice against the water element, and go, pissing Wade off.
As Ember is about to take over the Fireplace, Wade shows up and declares his love for her, while also letting her slip so she causes the pipe to break. Ember rejects Wade, but Cinder feels genuine affection.
Disappointed, Bernie decides not to retire and denies Ember's shop. When the new seal on the dam broke, the fire district flooded. After saving Blue Fire, Ember and Wade are trapped in a room in the Fireplace, causing Wade to evaporate from the sealed heat.
As the flood recedes, the grief-stricken Ember confesses to Bernie that she does not want to run the Fireplace and expresses her love for Wade.
Realizing Wade has seeped into the stone ceiling, Ember plays a crying game to make him return to his normal form. Ember reciprocates Wade's affection and they kiss.
A few months later, Wade and Ember, now a couple, leave Element City so Ember can learn glassmaking far away and travel the world together. Before boarding the ship, Ember bowed to Bernie who replied to the gesture.