Check out this clip.
I never put it online as I thought the guys who made it wouldn't want it up, but Ath, the guy who made it, has chucked it up publically so I thought I'd post it for you to check out.
To set the scene, the guys in the clip are in a sewer tunnel that is being built. You need to picture being on the site... avoiding security to get in... being careful... quiet... like Ninjas...
Try and watch the whole 9min 30secs - it's a bit repetitive in parts, but the first half builds up to the um, ahhh, what to call it... plot twist after 4.45.