The Detect Invisibility spell allows the caster to see invisible, hidden, or concealed hostile creatures.
When the wizard casts a Detect Invisibility spell, <PRO_HESHE> is able to see clearly any objects or beings that are invisible, as well as any that are astral, ethereal, or out of phase. In addition, this spell enables the wizard to detect hidden or concealed creatures (e.g., Thieves hiding in shadows, halflings in underbrush, and so on). It does not reveal the method of concealment or invisibility, except in the case of astral travelers (where the silver cord can be seen). It does not reveal illusions or enable the caster to see through physical objects.