The guard opens the door and makes way for you to enter. Inside you find a beautiful if gaudy atrium. Through double doors you can see a gala in full swing. Closed doors lead to the left and right. A stairway leads up to a second level, or possibly a balcony. There are a handful of party goers, mostly Human, in the atrium, but they pay no notice to you.
OOC: I let you take 10 on your attempt, which means you just assume you rolled a 10. Sometimes you can do this and sometimes you cannot; in this case, I didn't see any reason not to.