Barrier Spell

"He hadn’t seen it before, but a flickering green dome covered the entire house and stretched down at least half of the block. The green glow seemed to be weakening, and so was the rune on Alabaster’s leg. Even though it had been bright and sunny just moments ago, storm clouds now hovered overhead, bombarding the barrier with lightning strikes." (The Demigod Diaries, Son of Magic).

"Alabaster started to pour himself another cup of tea, then froze. One of the symbols scribbled onto his right sleeve was glowing bright green. “Lamia’s here,” he muttered. “I have enough power to keep her out for a while, but—” There was a brittle sound like a lightbulb popping, and the symbol on his sleeve splintered like glass, spraying shards of green light. Alabaster dropped his cup. “That’s impossible! There’s no way she could have broken my barrier with her magic unless she…” (The Demigod Diaries, Son of Magic).

"Before Alabaster could answer, another rune on his shirt exploded. “Get up! We need to go now! She just breached the secondary barrier.” (The Demigod Diaries, Son of Magic).

"Alabaster tapped a few more runes on his outfit and they all shattered. As if in response, a symbol on his pants leg started to glow bright green. “I’ve strengthened the inner walls, but there’s no way they’ll hold her long." (The Demigod Diaries, Son of Magic).

"He was about to argue when the glowing rune on Alabaster’s leg burst into flame. The boy winced in pain, falling to his knees. Above them, the green dome shattered with a sound like a million windows breaking." (The Demigod Diaries, Son of Magic).