Answer based on context:

The Vikings returned to the Metrodome in Week 3 for the first time since their 2009 Divisional Play-off to take on the Seattle Seahawks. Quarterback Brett Favre lasted for eight series and threw for 187 yards on 16 completions, but the Vikings only came away with 10 points while he was on the field. The first points of the game came from an interception of a Favre pass, as Seattle safety Earl Thomas got to the ball ahead of wide receiver Bernard Berrian and returned it for an 86-yard touchdown. Nevertheless, Darius Reynaud returned the ensuing kickoff for 73 yards, giving Adrian Peterson the opportunity to rush 23 yards in two plays to level the scores at 7-7. Olindo Mare and Ryan Longwell then traded field goals to make the scores 10-10 at halftime. Another field goal from Mare put the Seahawks ahead on their first drive of the second half, but the Vikings responded with a 25-yard touchdown pass from Sage Rosenfels to new wide receiver Javon Walker with just over seven minutes left in the game. Minnesota sealed the win with less than three minutes on the clock, when Joe Webb tossed the ball seven yards for fullback Ryan D'Imperio to return the Vikings to a winning preseason record.

How many points were scored in the first half?
20