Part 5/11:
The Combine’s invasion of Earth began with a catastrophic event known as the Resonance Cascade. Following this incident, Black Mesa Research Corporation inadvertently opened a doorway to the Combine’s realm, signaling the start of humanity's grim struggle. What followed was a rapid and brutal submission orchestrated by Dr. Wallace Breen, who became Earth's administrator and liaison to the Combine, promoting a narrative of cooperation that masked the regime's cruelty.