This elaborate key on a fine gold chain is always glinting even in the dimmest light. You may use it to lock (but not unlock) any nonmagical lock as if it were the proper key. Once per day, you may turn it clockwise once to activate a shield of faith upon yourself (though if you are chaotic it only provides a +1 deflection bonus).
If your patron is a good god, the key counts as a holy symbol. Once per day, you may speak a command word and summon a two-headed eagle as if using summon monster II (its extra head does not give it an extra attack). This eagle obeys your commands as if you shared a common language. While the key is worn as a pendant or held in hand, you can mentally add, subtract, multiply, or divide numbers with perfect accuracy, such as for distributing treasure or other resources, calculating interest on a loan, and so on.