Explosive runes

Explosive runes was an abjuration spell that booby-trapped runes to explode in their readers' faces.

Effect
The caster traced these mystic runes upon a book, map, scroll, or similar object bearing written information. The runes detonated when read. Anyone next to the runes (close enough to read them) suffered from this explosion.

The spellcaster and anyone else he or she nominated could read the protected writing without triggering the runes. Likewise, the spellcaster could remove the runes whenever desired.