18. Slip-up

There was always an invisible wall between Kristina and Tristan. A wall she was never able to tear down or climb over. Sometimes, on good days, it appeared to be as thin as a sheet of paper, but whenever she tried to get closer, to tear it down - she faced nothing more than a hostile brick wall. The message was clear, no matter the cruelty it held: 'Don't cross the line - This is as far as you can go.'

Tristan maintained this barrier around everyone. He never showed his true feelings - and if he did, it was only a slip-up. Despite being one of Kristina's few childhood friends, he never gave her anything more than the illusion of closeness.

The more time Kristina spent as Tristan, the more she was sure of her play. She owned Tristan's mannerisms, behavior, and way of speaking. The only one who could see through her act would be none other than the owner of the body she now inhabited - Tristan. 

Alec and Tristan were sitting in the dining room, going through some math problems that Alec struggled with.

Alec looked at a simple picture of a triangle and exclaimed with a frown, "Who even came up with this nonsense? When am I ever going to use inverse trigonometric functions?"

"In school, maybe?" Tristan suggested with a shrug.

"So it's useless in real life," Alec concluded.

"If you want to be a garbage man, then yes," Tristan smirked.

However, Tristan's smirk soon faded when he saw the other Kristina sitting down next to him. 

It's eerie to see your body and know that the consciousness inside it can't be you.

Tristan felt watched. Everything he said and did was carefully observed - every uneven breath he took, every twitch of his foot, excessive blinking, hesitation, dishonesty, pretense - Tristan felt as if the other Kristina could notice all these little holes in his almost perfect act.

"Teach me too, Tristan," the fake Kristina pleaded with puppy eyes, which was a rare sight on the face of true Kristina. She never pleaded like this - it looked forced. 

Tristan forced a smile. "You can watch. I bet you're smart enough to pick up, Kristina."

Her own name slid off Kristina's tongue like a rotten egg, coating her mind with spores. Mold, a curious entity presenting itself with those small caps, those miniature 'mushrooms,' while beneath the surface, the intricate mycelium stretches far, unseen, working its way without our awareness. We tend to fixate on the visible mushroom, often oblivious to the extensive roots beneath. It's a subtle invasion, a silent conquest.

"So, where did we leave off?" Tristan turned to Alec.

"I don't know," Alec shrugged. "But it's not like I need an A in math - so we can stop here."

Before Tristan had a chance to disagree, Alec left.

Thus, Tristan was left alone with Kristina.

"So," Kristina smiled, "I don't think you got this quite right." She giggled, pointing at the starting formula. "You confused these two," Kristina took his pen and scribbled a similar formula.

"But I don't think Alec noticed," the fake Kristina murmured. 

Tristan's eyes widen. 

An alarm went off. Kristina failed to imitate Tristan perfectly. She forgot how big their knowledge gap got over the years; she forgot how she lost the will to study and dropped out of school not long after Millen's death. To tell the truth, now, she's as lost in math as Alec.

"I thought you wanted me to teach you," Tristan tried to lessen the tense atmosphere.

Kristina merely smiled and stared into Tristan's emerald-green eyes. 

"I did," Kristina shrugged after what seemed like a lifetime.

She swiftly stood up, and before she left, she hugged Tristan tightly, squeezing his ribcage as if he were a tube of paint, and she wanted to squeeze out every last drop.

How could Kristina miss the carefully put-together facade of the imposter who wore her body? The fake Kristina, with her practiced smiles and feigned innocence, revealed only what she wanted others to see, like the hidden mycelium of mold.

Tristan clenched his jaw, suppressing the pain that radiated through him. Beneath his shirt, the vivid reminder of his father's anger lingered - an unsightly bruise clutching at his ribcage.

Does it know? The way her hand caressed his ribs before she disappeared. This knowing cuckle. Am I reading too much into it?

Tristan abruptly stood up. 

"Where did Kristina go?" Tristan asked in a rush when he stumbled upon Alec, who was watching TV.

"How would I know?"

"How could you-" Tristan stopped, "Forget it."

Tristan gave up for now. It seemed like whatever this fake Kristina knew wouldn't be easy to acquire.

He plopped on the couch next to Alec and closed his eyes. Alec watched his features relax - Tristan looked way more beautiful like this - in his calmness. Alec's hand lingered above Tristan's head before he decided to retreat it with a sigh.

'She knows something- something I don't. Can't even pretend to be me properly, tsk tsk tsk.' - Kristina wracked her brain. However, none of her hardboiled emotions reflected outwardly. 

Tristan's face remained relaxed. A way more relaxed than it should've been. 

He fell asleep. Alec turned off the TV and covered Tristan with a blanket.

"Sleep tight," Alec whispered before sitting back next to him.