Escape the Lab

Practice is over, and you're ready to head home. You've got a big Biology project due tomorrow on cells, but you can't find your lab notebook. The last place you remember having it was in Biology lab. Mr. Silverton, the custodian lets you in the building and you peer through the small window in the door to the lab. Dr. E, your Biology teacher, is no where in sight. Is that your notebook on the counter? The place sort of creeps you out during the school day, but it's really giving you the heebie-jeebies now. Why does your friend Joe always have to joke around about Dr. E being the modern version of Frankenstein, anyway? You slip in to the room and hurry to the notebook. That's it! You've got it made. You head back to the door and push. Locked?? Wait a minute. What's happened to the door? It's got some weird set combination locks on it. Shouldn't they be on the outside? Or is Dr. E trying to keep someone, or something, in?