You raise your spellbook as you magically rip the formula of a spell you know from its confines. Choose a spell of 1st level or lower in your spellbook with a casting time of 1 Action that you do not have prepared. You may cast that spell at its lowest level without expending an additional spell slot; if the spell has any verbal, somatic, or material components, it retains them.

Upon casting a spell this way, that spell is removed from your spellbook and you must re-inscribe it into your spellbook before you can cast it again*. If the spellbook has paper or parchment pages, the pages bearing the chosen spell's formula are also destroyed as part of casting this spell. You still know the spell.

*If you have multiple copies of the chosen spell's formula, you retain the ability to cast the spell as long as you have at least 1 copy available.

At Higher Levels. The highest level of spell you can choose for the alternate casting is always one level lower than the level of the spell slot used in De-scribe's casting.