I got to write the explosion, which wasn't technically an explosion but still lots of fun to write. Here's an excerpt at the start of chapter 29 (I have short chapters):
One moment Rafael and I were flirting, the next moment the roof had caved in and people were screaming. I hate it when that happens.
Pieces of wood and shingles rained down on us, and a big chunk of the ceiling landed on the table and scattered plaster everywhere. Rafael grabbed me and dived under the table.
I realized he'd cast a shield spell over us. He threw himself on top of me and I felt his energy feeding into the shield, pouring into it like me healing in a hurry. More pieces of roof fell around us. "Rafael, don't--you'll kill yourself."
"I'm fine," he gasped. "There's something out there. I won't let it hurt you."
The table sheltering us was flung aside, and I heard more screams. Plaster dust shrouded the room, billowing down from the ruined ceiling; it obscured my view through Rafael's shield, but not enough to stop me from seeing what was climbing in from the roof.
A dragon, red-gold and not quite solid. I could see the edges of the roof through it, and the cloudy sky.