Mid-chapter blues

Keioskie writes:

Ugh.  Don’t you hate it when you start a chapter with every intention of finishing it, yet the more you write the further away the end gets?  I’m right in the middle of a Chinatown massage parlour, my hero’s kicked down the door and is about to get the evidence he needs against a cheating husband, and then NOTHING.  I lose the thread.  My whole fantasy world is gone in a puff of smoke.  One minute I’m in New York, the next I’m looking at a flickering cursor mocking me and reminding me how many words I have yet to write.  The chapter is yet to be finished and I begin to wonder how I can scale the blank, white slopes when I don’t have any skis.

Any tips?