It is at dusk that our imaginations and fears start to play tricks on our minds.  The sun-filled, logical part of the day is over. Twilight deepens.  Looming shadows, the scuttling of animals, and eerie, indiscernible shapes; the witching hour approaches.  This is the time, walking home from work on a cold winter’s night, when your brain conjures up all those things that go bump in the night.  You walk faster, trying to get ahead of the possible footsteps behind you, jump at the tree branch when it brushes your shoulder, and peer ahead into the gloom, trying desperately to make out what the troll-like shape is in front of…