Both films treat a global catastrophe as an institutional and procedural story rather than as a hero's: parallel strands following scientists, officials, journalists and one ordinary family, cut together so that no single character holds the plot. Deep Impact is the disaster film that took the science and the policy seriously enough to give a president a briefing scene rather than a speech, and Contagion is that approach carried to its conclusion, with the epidemiology as the subject and the star cast deliberately expendable. Weighted low because the lineage runs through the genre rather than through any stated debt.