8 hours on one sentence

Yes, you read correctly - yesterday I spent the whole working day on one sentence. And, no, it's still not quite right. It's the last sentence I have to write, but it's not the last sentence of the novel - that was written days ago. This sentence is at the beginning of the fourth part - and I'm asking quite of lot of it. This poor sentence has to remind people what was happening at the end of the first part, remind them how the characters would react, and bring the tone down to quietly ominous. No pressure, then :-)