Complex sentence: When the emissary returns, Hazel and his rabbits learn Efrafa is a police state led by the despotic General Woundwort, and the four rabbits dispatched there manage to return with little more than their lives intact.
Split into simpler sentences: When the emissary returns soon after, Hazel and his rabbits learn that Efrafa is a police state led by the despotic General Woundwort. Holly and the other rabbits dispatched there have managed to return with little more than their lives intact.