Then perhaps we'll need someone waiting outside as well... No, more than one, for safety's sake. Someone will also need to man that window, and more than one person should know to send the signal, should our window watcher somehow be incapacitated in an emergency.

[ ... Also, he's very concerned about teens manning the charge here... Then again, children do tend to have the energy for this, and it's not the worst idea. Just need a few adults to keep an eye on the proceedings and point out the need for logistics, is all. ]