WASHINGTON — For reasons that aren’t particularly clear, Kris Letang abruptly departed his side of the ice while the Penguins were defending a one-goal lead the third period of Game 5 at Capital One Arena on Saturday.



The series, and Penguins-Capitals history, may never be quite the same.



Letang’s man scored twice in the third period as the Penguins lost a game they generally dominated in a 6-3 setback. The series, along with the Penguins’ championship reign, will be on the line in Game 6 on Monday at PPG Paints Arena.



A better form of Letang will surely be necessary if the Penguins are to advance past the Capitals.



His explanation for his decision to leave the right side of the ice in the first minute of the third period was a little curious. The Penguins were defending what should have been a two on two when Letang skated behind Brian Dumoulin on the left side of the Penguins’ defensive zone, essentially giving Evgeny...