He hesitantly quit that job to take a writers assistant position on NBC's Heroes; where he worked for two seasons.
[1][2][3] A friend of Doyle's let him know that Marvel Studios was going to be doing their first network television series, and if he'd want to submit for it.
His first script, season one's "Nothing Personal", was written under the supervision of co-executive producer Paul Zbyszewski, whom he co-wrote the episode with.
After the success of that outing, Doyle was given the responsibility of writing solo, during the shows sophomore season.
He has gone on to write episodes: "Melinda", "Purpose in the Machine", "The Team", and the heavily lauded "Many Heads, One Tale", with co-creator Jed Whedon.