Sims 3 world adventures Black Bag Job help?

When my sim entered the house, i had trouble finding the entrance to the base. It eventually opened when i took a book out of the bookcase and there was also a code: 617. anyway, i used the code for the first 2 levels and it worked, but i dont know what to do for the third level. I looked everywhere around the house for it; flushed toilets and turned radio off, but i cant find it. can someone help me find it or tell me the code or something? thatnks