Explosive runes

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

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

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