 Marshall and Lily finally have got the perfect place they always wanted to get married at. The only problematic thing about this is that the place is only available in two months. So, this means a lot of work for everybody. To listen to a band Marshall wants to play at the wedding, Lily,Barney and Robin sneak into a High School prom. While the other three are at the prom, Marshall and Ted, who had actually planned a "men s night", are wrapping up wedding invitations until Lily wants Marshall to come to the prom to. Of course, Ted comes along too.