In the build up to the season finale of "How I Met Your Mother," the stars of the hit comedy series delivered a funny countdown of facetious spoilers in the last episode on the "Late Show with David Letterman."

On Monday, the cast stopped by the late night talk show to participate in a short segment titled "Top 10 Surprises In The Final Episode of How I Met Your Mother." Although most fans are eager to find out if Barney and Robin will actually get married and if Ted will actually allow the wedding to take place, the actors instead dropped goofy hints about the closing finale.

"You know that bar we hang out in?" asked Alyson Hannigan in surprise number seven, referring to MacLarens, "We buy it and turn it into a Duane Reade."

Neil Patrick Harris read surprise number six, saying, "Together, Velma, Ted, Daphne, Shaggy, and I crack the case of the 'Arcade Arsonist.'"

Another reason to watch the series finale, according to Cobie Smulders is because, "For some reason, we're all naked."

For the third surprise, Josh Radnor said, "Someone finally points out that I don't sound like Bob Saget."

Hannigan continued, revealing that the second teaser on the list allows fans to find out how Ted met the Mother if they "send a self-addressed stamped envelope and $500."

There are only six episodes left in the ninth and final season of "HIMYM" and the countdown begins Monday, Feb. 24, with the premiere "Rally." In the upcoming episode, the gang will try to help Barney recover after he wakes up on the morning of his wedding with a major hangover. Ray Wise will also make a guest appearance playing Robin's father and add to the madness as Barney tries to recoup from his drunken stupor.

CBS issued a press release giving a synopsis of the upcoming episode that reads: "When Barney suffers from the world's worst hangover the morning of his wedding, the gang tries to figure out the far-fetched ingredients to concoct the Stinson Hangover Fixer Elixir."