Is there always light at the end of the tunnel?

There is usually light at the end of the tunnel, and to check this out I take a lonely walk down a Bangkok subway tunnel.

It's bright enough outside...


Still bright, as I approach the tunnel...


It's getting darker inside, but its quite cool in here, literally...


Wow it's pretty brightly lit and my hands are turning yellow now, but I can well see light at the end of the tunnel...


Hey light, here I come! Phew, that was quite a long tunnel for a pedestrian!