There was a single knock at John's door, and it was strange enough to cause him concern. He stood and hurried to the door, pulling it open to reveal Sebastia leaning against the wall. She was pale and shaking, face contorted in pain. John scooped her up, placing a comforting kiss against her forehead as her head fell onto his shoulder.
"Sebastia, what's wrong?"
"Poison," was all she croaked out. John mumbled a curse under his breath and set her on the couch, peering in her eyes and taking her pulse.
"Sebastia, we need to get you to a doctor. I can't treat poisonings. This is a flat, not a hospital." She tried to argue, but he shushed her, stroking the hair out of her face. "Listen, you are not in good condition. I'm not gonna let you die. Let's go." He scooped her back up and headed out the door. She spent the cab ride in his arms, mumbling weak arguments, insisting she was fine. He spent the ride shushing her, telling her he'd take care of it.
When they arrived he rushed to the front counter. "I'm John Watson, this is my sister, Harry. She's been poisoned. I'm not sure by what." The woman behind the counter nodded and phoned someone, and soon "Harry" was being rushed off with John clinging to her hand.
Once she had been treated John apologized for not having any id. Sebastia forked over the cash. They were out as soon as possible.
On the cab ride back to John's flat, Sebastia sighed. "I should be cross with you for taking me to a hospital against my will."
"But?"
"But I'm not dead, so thank you."
John smiled. "Just try not to take any more poison, yeah?"
She nodded and laid her head on his shoulder. "Yeah."