SPELL_INVISIBILITY

Usage       : cast invisibility <victim | object>
Accumulative: No
Duration    : 24 ticks, permanent on objects.
Level       : Level 4 mage
Mana Usage  : 5

This spell renders you undetectable to other living beings. Some
creatures have the ability to see invisible things, however, so be
cautious. Attacking while invisible will immediately break the spell.

See also:  DETECT INVISIBILITY