The union leader who represents the workers at the nuclear power plant disappears, leaving the employees without a leader to renegotiate their contract. Taking advantage of the situation, Mr. Burns removes the dental plan from his employees benefits package, offering free beer in return. The workers agree to accept Burns's plan, including Homer, until he realizes that he'll have to pay for Lisa's braces himself. At a union meeting, he stands up and urges the other members to reject the contract. Rallying them into a frenzy, he is elected the new plant union rep.

Without a dental plan, Marge gets Lisa the least expensive braces, which are crude and grotesque. Burns, unable to bribe or threaten Homer into giving in to his demands during negotiations, vows to crush him. The workers vote to strike.

Burns plays his trump card and turns off the city's power, but the workers' resolve remains firm. Realizing that he cannot compete against Homer's strong leadership, Burns proposes to reinstate the dental plan if Homer will resign his union leader post. Homer agrees, and Lisa gets brand-new, state-of-the-art braces.