Complex sentence: After this, Santini invites Pignon to move in with him; when Pignon turns him down, Santini snaps, a fight ensues, and Santini is institutionalized to recover from his emotional breakdown.
Split into simpler sentences: After this, Santini invites Pignon to move in with him. When Pignon turns him down, Santini snaps, a fight ensues, and Santini is institutionalized to recover from his emotional breakdown.