Mondstadt, summer.

The heat was unbearable, so much so that all the common people slept with their windows open in an attempt to get even a bit of coolness in their homes. This unexpected heat wave had surprised absolutely everyone, which is why all the inhabitants were on edge, making stupid decisions.

It was under these circumstances that Lumine, a renowned assassin in the business, was put in touch with a client who wanted to sink the monopoly of the wine industry. And what better way to sink it than to kill the manager, Diluc Ragnvindr?

Lumine wasn't picky when it came to the requests of clients whose lives and motives she had learned not to care about. Keeping her mouth shut and getting the job done to get the agreed-upon sum was all she cared about. So, she put on her black outfit to be as unnoticed as possible under the starry night, armed herself with all her usual equipment, namely daggers, revolvers, and other smaller blades hidden in unmentionable parts of the body, and went out to carry out her mission.

The high temperature was stifling. Her deliberately tight-fitting outfit clung to her skin, sweat beading on her forehead as she sucked in hot air that only amplified the unpleasant heat.

When she finally saw the Dawn Winery, this wealthy man's splendid estate, surrounded by perfectly tended vineyards, Lumine was in a sweat. The atmosphere was heavy, as if trying to dissuade her from the murder she had planned. But it wasn't the heavens that would make her turn back. Lumine was afraid of nobody.

Once the building was several hundred meters away from where she was stationed, Lumine decided to put on the last bits of cloth she had delayed so as not to be further burdened by the oppressive temperatures. Reluctantly, she put on her black leather gloves and put on a black mask covering her eyes that she had stolen from the local mafia, the Fatui. This way, if she was ever spotted, her assailants would think of an attack from this mafia, which would keep her off the radar.

Passing a hand to the back of her neck, free of her hair in a small ponytail, only some recalcitrant hair fell back into her neck to unite with her skin. Usually, she preferred to leave them loose, more especially as they were almost too short to keep them raised, but this day, by the current temperatures, it was an exception.

Step by step, she set out to enter the wealthy property of this merchant, before approaching one of the first floor windows, belonging to the kitchen according to what Lumine had memorized from the plan of the mansion that had been provided to her. Unfortunately, it was closed. Lumine could have broken a tile to infiltrate, but in this heat, she was convinced that a window was open, she just had to find out which one.

So she went around the house, eyes directed towards each glass reflecting the weak gleams of the moon that was being timid, until she spotted what she was looking for: an opening.

With the agility of a panther, she infiltrated the interior of the mansion where everything must have a value that Lumine would be unable to evaluate, in a corridor.

First obstacle crossed.

Now she had to get to the owner's room to complete her mission. Thanks to her knowledge of the place acquired beforehand, Lumine didn't have any difficulty to locate herself in this residence which was not hers, and in spite of the ambient darkness. It only took her a few glances to locate the doors of the different rooms on the first floor, which allowed her to deduce the location of the stairs.

Without a second thought, she engaged in these steps leading to the floor in order to finish as soon as possible with this murder. The upper floor had fewer rooms than downstairs, so it would be even easier for her to find the room where Diluc was sleeping.

With the door to the room in sight, she rushed towards the wall, dagger firmly in place between her fingers.

In a few moments, she was going to create a sad spectacle based on metallic smell and burgundy tints. But it had become the daily life of this assassin that was this radiant woman, she had become used to it.

Yet, as she was about to put her hand on the door handle, a sound snapped her out of her concentration; a sound coming from the open window on the wall right next to said door. Golden gaze turned without delay in the direction of this sound, on the alert, fingers tightening around her weapon to protect herself as her body stiffened.

In the window frame was a young man, in his twenties, with a singular ginger hair that everyone in town knew: he was one of the commanders of the Fatui mafia. The mask on the side of his head, which he hadn't even positioned to hide his face, was just another proof that he was indeed one of the high-ranking members of this organization.

And Lumine, at that moment, was wearing one of the masks they gave to their recruits.

Her body froze, the blue eyes in front of her piercing through her, passing by her little mask to reach her eyes and make her feel the desire of murder and blood that this man, Tartaglia, radiated.

Feet on the windowsill of the second floor, Tartaglia allowed himself to enter without a sound, without ever leaving the assassin's eyes.

Lumine's thoughts swirled in her head. What was one of the Fatui's top members doing here? He must have enough work to do, guarding the back of the leader of this despicable organization, "The Tsaritsa" as she was called, like a common dog.

But it wasn't until she saw a blade in the man's hand that it clicked in her mind.

He had come to assassinate Diluc Ragnvindr.

What a funny situation. Two assassins for one person.

In the assassination business, there was one rule that clients had to follow: do not hire two assassins to do the same job. Otherwise, it could create friction and random hazards on the job. But it seemed that the current client didn't care about this imperative rule. Lumine was sure to make him regret it.

At least, if she managed to get out alive.

In front of her, the man was moving fearlessly in her direction, in the direction of the door and the target. Without even realizing it, Lumine took a step back. She was afraid of nobody, yet the ease with which he approached sent a chill down her spine. The way he was moving, the way his bulging muscles were contracting, the way his T-shirt was sticking to his skin because of the heat, or the irrepressible urge to draw blood that she could feel, frightened the young woman.

Between colleagues in the same environment, he was surely not going to attack her. However, this domination which emanated from his person let foresee an imminent fight.

So when he stood right in front of her, towering over her with a good head, both of them in front of the door of their common target's room, Lumine couldn't make the slightest movement. She was clutching her blade so tightly that the handle was embedded in the fabric of her glove, and her breathing was coming in fits and starts, which only increased the heat around her. Those night-piercing blue eyes were fixed on her, as if judging her to determine if she should be allowed to live or if she was just an annoyance he needed to get rid of.

Yet, as that beastly aura escaped from the man, Lumine couldn't help but notice how badly he was sweating. Sweat was beading everywhere his skin was exposed, and the heat radiating from his body was unbearable. Lumine was already feeling hot, but Tartaglia's presence barely a foot away was making it worse.

Finally, this executioner and almost inhuman being had a weakness: heat. Lumine couldn't repress a smile to take place on her soft face.

The blue irises that had been scrutinizing her with domination until now gradually became questioning, as if they were looking for the cause of that smile. But Lumine didn't answer his question.

After all, they were both assassins right outside the door of the one they were supposed to eliminate. This wasn't the time for tea and conversation and getting to know each other. So Lumine began waving her hands in the air, trying to communicate with this intruder without making a sound. She pointed first to herself, then to the door, to let him know that she was there to kill the owner. Then, she pointed a slightly angrier finger than before at the man, then at the window he had come through, to let him know that he had to turn back.

Unfortunately, this attempt at communication only seemed to amuse Tartaglia more. The smile that he too was beginning to show seemed childish, but it was clear that the childish soul no longer existed in his person.

Raising his hand, he answered Lumine in the same way she had done. With his middle and index fingers, he imitated a person walking up and down the stairs and out the door of the house. Strangely, this way of using his fingers to get his message across was perfectly explicit, as if he had practiced using his fingers as a doll to entertain the audience.

However, despite his advanced communication technique, Lumine refused to go back to where she came from.

It's from there that the war of the signs started, to try to persuade the other without a word to leave this place both of them claimed as their territory. This little game lasted a good moment, until finally both of them froze on the spot.

The door to the room had just opened, revealing Diluc Ragnvindr, fully dressed in his usual attire, as if he was waiting for them, claymore in hand as the tip rested on the glossy parquet floor, and looking noticeably annoyed.

Blue and gold looked at each other, too surprised to have any rational thought. It was only when Diluc lifted the claymore to hold it over his shoulder, before throwing it forward while summoning a phoenix of fire, that both regained the use of their bodies.

Tartaglia was the first to react, grabbing Lumine by the waist to pull her towards him, sticking her body to his as he threw himself through the open window to dodge the elemental behemoth. As soon as they were in the air, Lumine deployed her glider, allowing both of them to land gently before resuming their frantic race to leave this smelly property as soon as possible.

Mission failed. But for the time being, the two assassins who had been arguing with each other with childish signs, became the best allies as they headed towards their common client.

With these two forces at work, no doubt he would bitterly regret having broken this unspoken law in this dark world.