I did a 10k run on Saturday but it was a "military style" 10k run which comprised running flat for about 2 k then up the side of a hill onto a moor across the top for about 2 k through the cloud where every step you would sink up to your ankle. Then down for about 1k then through flat mud again the rest of the way with some cargo nets to crawl under and bog pits to contend with.
Did that in 1hour 4minutes

Woot!
So, I'm doing a flat 10k road race at the end of November. What's a reasonable time to aim for?