In the Glee 'Mattress' episode, how does Will allow the kids to perform at Sectionals?
In the "Mattress" episode of Glee, Will Schuester allows the kids to perform at Sectionals by faking an illness. He realizes that Sue Sylvester, the cheerleading coach and one of the Glee club's main antagonists, is planning to sabotage their performance by leaking their setlist to the competing teams. To counteract this, Will pretends to have a contagious disease (the "Monkey Flu") and is quarantined in the nurse's office, preventing Sue from getting close to him.
By doing so, he keeps the setlist a secret until the last moment and gives the Glee club a fair chance to surprise the other teams with their performance at Sectionals. This tactic ultimately helps the Glee club succeed and showcase their talents without interference.