Isidora Morganach's home, or at least one of her homes—Sebastian wasn't quite sure—it had plenty of notes and discoveries on her adventures travelling after graduating from Hogwarts, some keepsakes from other countries, and plenty of chests already emptied out.

The home was ancient and very worse for wear, the roof had long since caved in, allowing the rain from above to patter against both you and Sebastian. You had spotted a deep cavern within the corner of her living room, big enough to fit the both of you.

"After you," said Sebastian, gesturing to the dark, black entrance. It had been two years since you'd dealt with anything related to Isadora and the sudden discovery that one of her homes was merely a broomstick flight away from Hogwarts felt troubling to your intuition.

Your search was cut short when the moment you reached the end of the slope into the cave, a six legged beast jumped you. You recognised it as a hatchling, small for its kind but big enough to knock you off your feet. You attempted to reach for your wand but the large pincers found your arm, the hollow fangs sinking into your tissue. The venom soaked into your muscle drop by drop, your veins spreading black.

"Incendio!" The spider was thrown off of you with a quick ball of flame and Sebastian replaced it, kneeling at your side and pulling you up. He cursed, then took your wrist in his large hand and pushed back the fabric of your sleeve, bringing your numbing arm to his mouth. He latched on, sucking twice against your raw skin and then spitting to the floor next to him. Again, he sucked on the bite then spat out what he hoped was most of the venom, and what looked to be some of your blood, and perhaps some rainwater.

Through the haze of the sickening poison flooding your system and the feverish puffs of air you let out, you could hone in on Sebastian’s final part from your irritated skin. A thin, watery string of spit connected him to your arm before it broke and he turned to gauge the effects of the venom on your face.

You insisted on continuing to look throughout the cave much to Sebastian's chagrin. He noticed this, like most things about you. You were the most self-destructive individual he'd ever met, and the only thing keeping you from dying alone after some stupid "investigation into Ancient Magic" was him.

He took his role very seriously.

"The house won't be going anywhere, we can come back when you're well again," Sebastian argued, slipping an arm under your knees and carrying you bridal-style away from that godforsaken spit of land, sneaking back into the castle.

He muttered something about Peeves when you entered, your arm around his shoulder and a light hand on your side, keeping you steady as though he was a friend helping you home after a night of drinking. You needed a brewing stand to rid you of this horrid, sickening ache and the fuzziness behind your eyes.

"What in Merlin's name?" A nearby wall began to shift, swirls of a door began to form and you had never been so relieved to see the entrance to the Room of Requirement form for you. It felt like a dear friend coming to your aid. 

"Just when I think there are no more bloody secret rooms..." Sebastian grumbles, and your small chuckle turns into an awful coughing fit fast enough for him to take action immediately, setting you down carefully on the closest thing he could, which happened to be a plush settee, making himself comfortable with your potions stand to brew Wiggenweld.

After you drank an entire vial, your vision began to clear and you could finally take in the extent of Sebastian's worry, his face seemingly pulled into an eternal frown. He watched your eyes keenly for any haze or sickly glossiness, kneeling in front of you on the floor, hands on your knees. "Another?" He asked casually, but his hand shook and his voice wavered and he was so fucking scared back there and, Merlin, he really hopes it wasn't obvious.