The gang decided to visit the bears and were not greeted warmly. Harpo, Groucho's brother, was running the tribe in his absence. He had capitulated to the Watchers.
Groucho dominated his brother and showed strength to the tribe. With one mighty strike, he felled his brother, who collapsed with a punctured lung. That's when the Watchers arrived. Groucho instructed the clan to save there fight for another day and allowed the Watchers to drag his brother off.
Groucho left his grandmother in charge of the tribe and insisted that they prepare to fight the Watchers, gaining yet another cell for the Resistance.