I just felt like doing a word prompt and see where it goes. Nothing too serious.
Smoke was a strange smell to Karkat, before and after the accident. The definition and its origin were simple; as long as there was smoke, there was fire. However, whatever that fire burned made a unique smell.
The few camping trips he and his dad ever took was filled with the oaky smell of burning firewood. The smoke was always a welcoming thing then, as that smell of burning wood was followed by smores and burnt hot dogs on sticks. The fact he always made his marshmallow extra crispy certainly added to it.
Burning candles or incense may not be related to smoke, but Karkat counted them simply because of the smell. Some made his throat close up out of the occasional allergy, but they usually smelled nice when Aradia went through occult phase and stole some of her mom's scented ones.
The smell of cigarette smoke was an unwelcome one, and it the one that always clung into everything. His father used to be a heavy smoker back when he was younger, and Karkat had convinced him to quit after getting the usual spiel about them being bad for his health. Even after years of being off the stuff, Karkat would catch the occasional whiff of it on a piece of old clothing. Like something didn't want to leave them.
The worst type of smoke was the kind he smelled when a car had caught on fire not far down on Karkat's street. A car had an engine failure while it was driving down near his house, and after the driver abandoned it to get a mechanic, smoke had started to rise out of it in a flood. By the time somebody had come down to stop it, it was already on fire and Karkat would smell burning gas from a mile away.
It had been a suffocating smell, taking over everything else. The smoke had risen up and up, disappearing into the sky as the car went into a large blaze that he thought he'd never see again.
Karkat wasn't sure what his smoke reminded him of, really. Whenever it came out of his throat and into the open air, he never had enough time to actually see it fully, much less smell it.
But then again, it wasn't there as a luxury. Where there was smoke, there was fire, and it just happened to follow him everywhere.