The official score read: 3-unassisted, 9-3-6. The visual was even more mind-boggling.
"Never," Castillo said when asked if he'd been part of such a unique play. "I asked [Nationals right fielder Elijah Dukes] if he got the ball, and he said he got the ball. But the [first-base umpire Derryl Cousins] said he didn't have the ball."
With Castillo on first base after walking to lead off the fourth inning, the Mets would stunt a potential rally with a zany double play that proved to be a crucial turning point in an eventual 7-1 Nationals win.
Castillo, who believed Dukes caught Brown's fly ball on what proved to be a sliding trap, retreated all the way back to first. As Brown tried to stop Castillo, he overran the Mets' leadoff man and was immediately called out -- officially ruled a 3-unassisted. Castillo proceeded to touch first, and took off to second, where he was cut down on the relay. Dukes, from the seat of his pants, threw the ball to first baseman Nick Johnson, whose relay to shortstop Cristian Guzman completed the zany twin-killing.
"I thought he caught the ball, and when I tried to stop, it was too late," Castillo said. "The umpire wasn't making the call right away. I think I tried to be too aggressive."
Ultimately, it was the fourth straight inning to open the game that the Mets grounded or ran themselves into a double play.
"We knew on the bench right away that Emil Brown was out, because he passed the runner right away," Nationals manager Manny Acta said. "We were hoping our kids would throw to the right base and get the right guy."
Mets manager Jerry Manuel called it the turning point in the game, and discussed the call with the umpiring crew immediately following the play because he felt "there was no clarity to the play."
"The confused double play was a big play," Manuel said. "It looked like it was headed toward the gap, and [Dukes] cut it off and made a nice play on it. We were a little confused on the bases on that, and obviously ended up with two outs there. I thought that was the turnaround, with the top of the order. That was kind of the turnaround period there."
Nationals pitcher John Lannan, who used a two-seam fastball for the other four double plays, retired the next 11 batters en route to his first career complete game.
The Mets grounded into another double play to end an eighth-inning rally. The five double plays the Nationals turned set a new team record -- the most the club has induced since moving to Washington -- and tied a franchise record, which has been done four times, most recently on May 13, 2003, in San Francisco.
Sean Welsh is a contributor to MLB.com. MLB.com reporter Bill Ladson contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.