How do you make a heist interesting?

Sounds like a stupid question, after all how many books and movies are based on that very idea?

But unless the heist is the actual focus, it's pretty hard to make a heist interesting these days. I mean, unless you want to spend chapters coming up with twists and turns.

Which just goes to show that the heist isn't the point of "Shadows over Summer House," but more of a plot device that motivates the characters. A McGuffin so to speak. 

Really, this is just a strong-arm robbery. Busting in, tying people up, grabbing the money and running.

So, yeah, I can have everything go wrong. The bad guys show up, one of the robbers betrays them, and so on and so on.

But really, it's just a fucking heist.

I could probably say the same thing about the gun battle at the end--but I have a nice little trick up my sleeve on that one.

So I've spent one day already mulling over my heist, waiting for something that really clicks, that will make the scene interesting and involving. I know it's out there somewhere, but I'm not writing it until I've got it figured out.