31,000 words is a great start to a mystery! In the genre I write for, it is a good total length right there. The 30K to 60K novella is very popular with readers. Long enough to be emotionally involving, but short enough not to demand too much reading time. As for me, I have managed to start that fiction project I mentioned, and write the first 1400 words on the much-dreaded beginning. Hope the momentum will pick up soon. Writing dialog usually helps with that.