In the Glee 'Vitamin D' episode, it is revealed that Terri Schuester, the wife of Glee club coach Will Schuester, admits to the second performers that the first mash-up (performed by the New Directions) was done while the members were under the influence of some sort of drug, although the exact substance is not specified. Terri had covertly given them the drug in order to boost their performance and win the competition against their rivals, the Treble Makers. This confession leads to tension and conflict among the members of the Glee club and ultimately causes Will to question his leadership and methods.