The Exploding Meatball Sub [SEP] series
The Exploding Meatball Sub
"The Exploding Meatball Sub" is the 20th episode of the sixth season of the CBS sitcom "How I Met Your Mother" and the 132nd episode overall. It aired on April 11, 2011.
Plot.
Ted and the others realize how much he and Zoey argue, a polar opposite of Lily and Marshall’s relationship, where the two always seem to be in support of each other. Ted and Lily argue throughout the episode about whose relationship is better. However, Ted begins
it. Barney explains the real reason: some time ago, Marshall had pointed out some marinara sauce on Barney's suit while eating a meatball sub. Extremely irked by this comment, Barney spent months plotting his revenge, designing an exploding meatball sub to give to Marshall. Marshall had quit on the day Barney had planned to have Marshall receive the sub, denying him his chance at revenge.
In the end, ten years later, Barney is shown apparently on his death bed, with his grieving friends beside him.