Dreams have long been a point of contention for psychologists, full of vehement and loud opinions on what they mean. Some think that it's the brain going over the events of the day, while others postulate that it's the subconscious finally doing something useful and resolving issues. The smartest scientists are always identifiable by bedhead and coffee, because they prefer to experiment with sleep rather than theorise about it.1
What few scientists bother to worry about is whether or not plants dream. They do. In the plant community, Venus Fly Traps are noted to have the most vivid nightmares, which typically involve sunlight and arachnids. Creeping Vines rarely ever have dreams, being so exhausted from all the creeping.
The dreams of flora relevant to this story, however, are cactus dreams. The layman would think that cacti dream about water. This is not so. Dreaming about water is incredibly boring. Water by itself doesn't do much, other than fail to have the common decency to hold a definitive shape. A cactus dreaming about water would be comparable to a person dreaming of an open field. It sounds very poetic, but begins to drag on once you realise there's not much to do in an open field. The very idea is silly, preposterous, and implausible.
No, most cacti dream of finding a nice cactusette and settling down in that nice bit of sand just a block away from their good cactus friends. Cactusman, known to his friends as Daniel MacIntyre, or urrgghjhggjdf2 to very pretty cactusettes, was dreaming of settling down on that fateful morning. In particular, of Carrie (RH) Ipsalsis, who was, while not a cactus, very pretty. Cactusman himself was not actually a cactus, but an upright member of his human community, dedicated to saving innocent lives and preventing dehydration.
It was with a grunt that he was awoken from his slumber. Specifically, a grunt that meant "Hey, Daniel, wake up!". Rubbing the sand from his eyes, Cactusman glared blearily at Carl from across the room. Carl was a handsome specimen, a strapping male in the prime of his youth, who had met Cactusman at their local home improvement store. Carl was also a cactus, which may raise the question of how he was currently speaking to Cactusman.
Carl, as any reasonable person could assume, was not speaking in English, but in Cactese. Cactese is entirely incomprehensible to the human ear, who hear it mainly as a series of roars and grunts. It is actually a much more complicated language, with 13 specific grunts designed to obfuscate any humans who might be planning on pillaging innocent cacti and putting them up as trophies on their mantle. There are 73.5 words to describe a small amount of water in cactese, because cacti are predominately optimists, and not nearly as prickly about glasses being filled with water as humans.
"Daniel, wake up man! Someone needs your help!"
Like a slap in the face, or being stabbed by the spine of a cactus, Daniel jerked up, throwing off his sheets and rushing off to grab breakfast by the window. A hero can't be expected to save the day without energy, after all. Carl continued to speak, giving Cactusman the minutiae.
"Her name is Lily, I met her at the plant nursery. She always made sure I had enough water and sunlight, great gal. Pretty, too, man, you should have seen her-"
"Carl! Get to the point!" shouted Daniel, cutting Carl off in the middle of his diatribe.
"Right, right, sorry. She was kidnapped, Dan! They stole her away! You gotta rescue her, she's a damsel in distress! They took her to 5739 North Clark!"
Spurred on by his heroic and solemn duty, Cactusman dashed to the door. His thought traveled faster, though, and he paused, turning to Carl. "Where'd you hear this from, anyways?"
"Oh. I heard it from the grapevine."
To describe how long Daniel stared at Carl would be an impractical waste of text, and would also imply that something other than staring happened in that timespan. Staring is a very dull thing to write about. There are only so many ways to describe a stare, and the majority of them are variations on "intense". To create a clearer picture of what happened, stand up, find a plant, and stare at it for ten minutes. This story will still be here.
Welcome back. Yes, it was that boring.
Daniel tore his stare away, muttering something about "that incorrigible gossip" before dashing out the door, spines drawn taut in preparation for the battle ahead. Today, evil would not stand. Today, the world would be bathed in light and righteousness.
Cactusman trudged through the torrential downpour, peering up occasionally to look at the street numbers. The path of righteousness be damned, the weather had other plans. It had been behaving itself, sunny days and mild temperatures for too long. It had been saving itself for this day, which it had marked down on the calendar it stored up in the cloud. Useful thing, the cloud.
By the time Cactusman found 5739 North Clark, he was wetter than any cactus had a right to be. Cacti tend to like the weather like they like their humour: dry, and preferably involving George Carlin3. Taking a spine from his back, Cactusman quietly investigated the integrity of the keylock, then very legally and equally quietly entered the threshold.
"I'm in the belly of the beast now…" thought Cactusman, as he surveyed the room. It was obvious that there was no one home, from the state of the apartment. The TV wasn't on, and he wasn't being angrily questioned about why in the hell a stranger is standing in our home and how did you get in I'm calling the bloody police Bob get over here and teach this hoodlum a lesson again.
It wasn't really the wretched hive of villainy that Cactusman expected. The place was downright pleasant. They had obviously put work into the breakfast nook which was dotted with potted plants, and the couch went very well with the rug. The whole living room was so open and inviting- "WHO THE HELL ARE YOU!?"
The owner of the particularly angry vocalisation was an equally loud Hawaiian shirt, filled out by a rotund man, the kind who is usually accompanied by a beer and plastic pink flamingos. What he was doing here was unknown. Maybe he was lost. It would certainly explain why he was so angry.
He greeted Cactusman with an enthusiastic fistbump to the jaw, his arm hurtling through the air like a porcine train car carrying sausages4. Cactusman's world exploded with new colours (such as sillown), reeling back from the force of the blow, more than enough to ruin the day of any cactus.
Cactusman caught himself on a nearby coffee table, as the Hawaiian shirt was busy marveling at the new cactus spines growing out of his hand. His revelations were loud and involved hopping and shaking his hand. Grasping blindly behind him, Cactusman found a friendly coffee mug, and brought it down hard over the Hawaiian shirt's head, in accordance with the celebration.5
The Hawaiian shirt crumpled to the floor, and Cactusman stepped over the ne'er-do-weller gingerly, making a mental note to call the hospital, and maybe iron out some of the wrinkles. As he was idly wondering why Hawaiian shirts were acceptable fashion, a muffled shout brought him out of his reverie.
A shout! The damsel in distress! Cactusman dashed to the source of the noise, bursting in the room next over. And there she was.
A sight like Lily was one that a man would never forget. Even in their old age, as they ramble on about lawns, hills biting their ankles as they climbed up wolves on their way to school, they would remember that moment. She had a flower, tucked in on her head, accenting the soft colour of her body. The light streamed into the room, highlighting her pretty face as she implored Cactusman to save her from the bindings that constrained the curves of her body, a price tag poking out of the soil in her pot.
All things considered, she was a very pretty cactus.

Footnotes
1. Most theoretical discussions about dream meaning usually end up in a group double blind sleep experiment, so the point becomes moot by the thirtieth sheep.
2. Imagine a noise very similar to gargling kidney stones
3. Woe betide those who try to give a cactus Leslie Nielsen though.
4. Or the fist of an angry fat man, if you don't enjoy similes.
5. Cacti rarely party, but when they do, they lose several friends, wake up with terrible hangovers, and often find most of their glassware shattered. It's why they're so often found in the desert. It's dry, miserably hot, and there's not a drop to drink anywhere. Not conducive to parties at all.