In Lisbon, a team of scientists has uncovered a more intricate truth about how SARS-CoV-2 enters the human cell — not through a single forced intrusion, but through a coordinated two-step mechanism embedded in the virus's spike protein. The discovery, published in the Journal of Virology, reveals that two distinct fusion peptides work in sequence, the first establishing contact and the second destabilizing the membrane from within. In mapping this molecular choreography, researchers have not only deepened our understanding of one virus, but may have illuminated a shared vulnerability across an