Conceptual Design 

Upon coming across the first box (you can't miss it, it's painted like a candy cane), you must solve the riddle inside of the box. This box will be unlocked. When you have entered the correct answer, the light will change to let you know. Then, you must search for the next box. You will know the box is the right one if the green "activated" light is on, and the box is unlocked. Again, repeat, and answer the riddle by dialing the potentiometers correctly. The light will change to let you know your answer is correct, and that the final box, wherever it is, has been unlocked. For the final box, once you find it, there is one final riddle. You can trigger the beer compartment to unlock by speaking the answer to the riddle. If you reach the final box too early, it will be locked and the voice trigger will not work. 

The related context is that the boxes will be stored in dry places on campus. Each box can remotely be re-locked as long as the user closes the lid after using the box.