In which Dr. Arrowsmith, feeling bereft without his friend Terry, confronts the discomforts of high society and the estrangement from an old companion whose crude commercial schemes clash with his scientific ideals, while his wife Joyce endeavours to bridge the chasm with thoughtful gestures and a new home laboratory. Yet amid the tensions of friendship lost and domestic unease, Martin clings to the hope of renewal through his work, resolved to reunite with Terry and reclaim the devotion to science that sustains him.