HOW I MET YOUR MOTHER Episode 9.18 Photos Rally : “Rally” — 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, on the final season of HOW I MET YOUR MOTHER, Monday, Feb. 24 (8:00-8:30 PM, ET/PT) on the CBS Television Network. Pictured: Neil Patrick Harris as Barney. Cobie Smulders as Robin. Alyson Hannigan as Lily. Photo: Ron P. Jaffe/Fox © 2013 Fox Television. All Rights Reserved.