wonderful story. I've read over 100 harry potter fics, and this is the best development of Harry's Slytherin side ever.
You have a great mix of actiona, tension, plot development and character development in the first 6 chapters.
The one addition that I would love to see is textual joiners between scene changes besides the horizontal line. The horizontial line is over used. working onf creating words which transition a reader from one scene to a next the biggest lack that I see in your writing. Figure that part out, and you will be one of the best.
Keep up the splendid work, and I can't wait to see what happens when Tom finds out that Harry knows the Indigo.