Answer based on context:

 This game was played in the shadow of the death of WR Torrey Smith's brother, who had died in a motorcycle crash the night before. The Ravens entered the game hoping to be able to avenge the AFC Championship loss of the previous season, which came at the hands of the Patriots.  New England started off fast as they drew to a 13-0 lead in the first quarter. However Baltimore scored 2 straight touchdowns to take the lead with 1:47 left to go in the half. Then Brady scored a touchdown right at the end of the half to retake the lead 20-14. The second half started off with a touchdown pass from Flacco to Dennis Pitta to put the Ravens on top 21-20. Then the Patriots retook the lead when Tom Brady scored a touchdown. After that the Baltimore defense began to step it up and held the Pats to a field goal. Then the momentum shifted as Baltimore scored a touchdown (Flacco to Torrey Smith). After forcing a Patriots punt, the Ravens drove down the field to score a field goal as time expired to win the game 31-30. The Ravens avenged the AFC Championship loss and improved to 2-1 and continued their unbeaten record at home from the previous year along with continuing their streak of winning after a loss. Based on Torrey Smith's performance through personal hardship, this game was ranked #9 on NFL.com's Top 20 NFL Games of 2012 as Showing Up. Smith finishes with six receptions for 127 yards and two touchdowns. This game was also remembered for 2 controversial incidents. Late in the 4th quarter, with New England leading 30-28, coach John Harbaugh was penalized for unsportsmanlike conduct for coming out onto the field, which by NFL rules, is prohibited. However, Harbaugh was claiming that he was trying to only call a timeout to save time for his team. Since the NFL was using replacement refs at the time, and not the original refs, this was another controversial incident involving replacement refs. The penalty resulted in an irate Ravens crowd chanting the word "Bullshit" 3 separate times in just over a minute during the Patriots last drive, which was picked up by NBC microphones and was clearly audible during the broadcast. Play-by-play announcer Al Michaels said "That's the loudest manuere chant I've ever heard". The other controversy is the winning field goal by Tucker. The ball, after it had been kicked, sailed over the top of the right upright. It was ruled "good", giving Baltimore the win. However, clear replays show that the ball was awfully close to sailing wide of the upright, which would've resulted in the kick being no good and giving the Patriots the win. Since field goals are not reviewable, the play could not be reviewed. Patriots coach Bill Belichick, as he was leaving the field, grabbed one of the officials, resulting in him being fined $50,000 by the NFL.

How many points were scored in the second half of the game?
27