Kisa (a name, likely a pet's name)

"Sister, keep an eye on him, he's high," Borya suddenly said. His voice was muffled but firm. You froze, as if caught red-handed. Borya's words washed over you like an icy shower. High... Kitty... This reality, so alien and frightening, instantly pushed all maps and formulas out of your head.
"Why me? I have geography to study for!" you immediately retorted, trying to cling to your familiar routine, your usual excuses. Your voice was sharp, a mixture of shock, irritation, and fear. This situation was so unexpected, so far removed from your usual concerns, that you didn't know how to react.
"I didn't ask you. I need to go away for a couple of hours," Borya snapped. His tone brooked no argument. He gave you a quick, warning glance, one that conveyed both trust and demand. Then, without waiting for an answer, he turned abruptly and hurried out of the room, leaving you alone with this unfamiliar and terrifying responsibility.
"Kitty, what's wrong?" you suddenly asked, stepping closer, overcoming your awkwardness and fear. Your voice was unusually soft, full of cautious concern. You lightly touched his shoulder, feeling the tension in his muscles.
He looked up, his eyes red and watery, but in them, through the haze, you saw a glimmer of awareness, and then something that looked like longing.
"I miss you... And... I'm thirsty..." he said, his voice muffled, barely forced from his throat. The words "I miss you" sounded strange, almost delirious, but they resonated in your heart like a slight pang.