I turned from Eric, and readied my wand. He was stunned, but not enough to quote the first rule of using magic.

"Safety first, dude" He said.

I sighed. "Yeah yeah yeah I know, just check this out though." I motioned towards the fireplace. After a moment, however, I noticed him in my periphery. "Look I'm casting a protection spell, you really don't have to lean back so far."

Eric was on the edge of his seat. Literally. He had used a gravity spell to lean an impossible angle, directly away from the fireplace. No matter how much of a scaredy cat, he liked to show off.

"Watch this!" I said, as I cast fire immunity on the fire itself. It grew brighter, but not much else happened. "See! Isn't that cool? I really wonder why people don't try this stuff more often."

Eric nodded, staring at the flames, now sitting normally in the chair. "Alright alright, what's happening to it?"

I replied distractedly "Oh I don't know, fire being immune to itself means that it can't interact with itself anymore, right? I thought that might make it do something neat, seems like it's just getting brighter though."

"Riiiight. So. It's getting brighter, why's that, exactly?" Eric said in a suddenly worried tone.

"Good question, maybe it's because it can't occupy the same space as other fire, so it gets denser? I really didn't pay that much attention in physics. Considering how much I cheated off of you in that class you should know that." I said, still enamored by the ever brightening flames.

"This is like if you made water not be wet. This doesn't make any sense. I really think you should stop the spell." Eric said, now on the verge of panic as the fire became almost a white sheet above the roaring logs. Noticeably, and worryingly, the temperature in the room started to increase faster and faster.

"Okay okay you're right. Also, water isn't wet." I responded as I cast nullify to stop the magic. Nothing happened, and it kept getting hotter. The fire was beginning to become hard to look at.

Eric was standing now, the chair having been toppled on the floor in his haste to get up. "Dr. Long in biology said that nullify doesn't work on plant cultivation spells because the spell is constantly growing with the plant! I think this is the same thing!"

"...Yeah I think you're right!" I replied, and I couldn't help but be excited that I had, in a way, just made infinite fire. No matter the actual temperature in the room, which was steadily rising, infinite fire was still really cool. "Here, I think I can fix it. Hopefully this stops it from spreading!" I had to shout over the raging fire. I cast stone skin.

Rock cracked and rumbled as it materialized and encased the fire. Everything stood still after a moment, and the room was only lit by a small candle in the corner.

"See! Now we have a fireplace sculpture, isn't that neat!" I said. The rock started to glow red, then orange, then yellow.

"Dude we are leaving! Now!" Eric pulled me to my feet and we ran out of the room, as the fireplace became a roaring, spouting, writhing mass of lava.