You are almost at the door. This is the crucial moment.
If you get this wrong, you've lost the book. And that will cause everything to go wrong. Everything you've worked for.
Carefully you sidestep the security tag reader. So far, so good.
But will the doors still be open? You glance ahead of you and you can just see the sliver that is all that is holding this plan together. Yes, they are.
You run forward, careful of tripwires. This place has high security. But why? Who would want to nick books?
That's what you are trying to find out.
But first, you need a book. This book. The one in your hand.
You squeeze through the gap in the door, and you are out in the night.