When Barney won't bounce back from his night of drinking, Ted and the gang set out to find the secret ingredient to Barney's Stinson's Hangover Fixer Elixer. They each also vow to never get drunk like their friend ever again. Ted then recounts the time when each of his friend's broke that vow. When they learn the elixir was just a placebo given to them by their good friend to cheer them up, they return the favor by telling him a legendary lie.