Lair: The Homebase

The teens will want to have a home base. A lair, in most senses of the word.
There should be central locations for most of the different types of things, but there should be a central spot for the characters that can include protections and hangout spaces and romantic nooks.
This should essentially be the LI's home, or at least where he stays most of the time. Gives us a reason for the MC to pop in and out but possibly remain unaware of what is going on. 

• Clubs! It's a clubhouse, we'll figure out what it's called otherwise
• What does it look like? What are the touches that the Mentor made to make it his own?
• It's at the school
• "club room"
• Definitely has secret compartments and things
• SECRET TUNNEL!
• It's more in the basement or ground level because of ease of access
• If one were sensitive to magical energies, this would be a hotspot
• There's a whole big bookshelf full of ancient tomes that the Mentor (aka a history teacher) uses for his students