Ryan Mallett was named the starting quarterback for the 3rd straight game of the 2015 season for Houston. After a dismal 1st half, the Falcons lead the Texans 28-0. In the fourth quarter with the Texans trailing 42-0, Mallett was pulled in favor of Brian Hoyer. Hoyer immediately performed better, passing for 2 touchdowns. However, to add insult to injury on what was already a bad day, with 1 second left to play on 4th and goal, Houston fumbled the ball with Nathan Stupar recovering it for an 84-yard touchdown. Taking the knee on a two-point conversion, the Falcons finished with a 48-21 victory.. What was the halftime score?