Runner on 1st when the ball is hit to center. The fielder makes the catch with the runner on 1st 1/2 way to 2nd and the fielder throws to 1st but throws ball out of play were does runner on 1st advance to.
The runner will be awarded third because the runner is awarded two bases from the base last occupied at the time of the play. However, since the ball was caught he must first retouch first and then continue to third. If he does not go to retouch the base then, once the ball is put back in play, the defense can appeal to first in order to get the runner out. This is a unique situation, however, because, since the ball is dead, after the runner touches the next base (in this case second) while the ball is dead then he will not be allowed to return to retouch first.
The umpire is not allowed to let the runner know that he must go retouch first and should not indicate either way that the runner forgot to retouch. If the runner tries to retouch first after touching second during the dead ball the umpire must tell the runner to continue to third and that he cannot go back to a pervious base after touching the next duringa dead ball.