This spell causes the recipient to vanish from sight and not be detectable by normal vision or even infravision. Of course, the invisible creature is not magically silenced with respect to noises normal to it. The spell remains in effect until it is magically broken or dispelled, or the magic-user or the other recipient cancels it or until he, she or it attacks any creature. Thus, the spell caster or recipient could open doors, talk, eat, climb stairs, etc., but if any form of attack is made, the invisible creature immediately becomes visible, although this will allow the first attack by the creature because of the former invisibility. Even the allies of the spell recipient cannot see the invisible creature, or his, her or its gear, unless these allies can normally see invisible things or employ magic to do so. Note that all highly intelligent creatures with 10 or more hit dice, or levels of experience or the equivalent in intelligence/dice/levels have a chance to automatically detect invisible objects. The material components of the invisibility spell are an eyelash and a bit of gum arabic, the former encased in the latter.