Invariably its the head light of the oncoming train. The tunnel is safer when its dark and eternal. When all you got is your own dying flickering candle. Is this pessimistic or just metaphorical judo with a dash of Murphy’s ? I’m too dim (this is a tunnel after all) and hurried to peer further into the gloom for meaning. So your wisdom will have to light the way. The comment box awaits to be lit with your words.