Ten years ago, a massive fire broke out at Guest's house.

While I was trembling in fear behind a door that wouldn't open, a firefighter risked his life, breaking through the door with his shoulder to save me.

Park Kang-hyuk.

That day, a permanent scar was left on his right shoulder, and the only thing he said as he gently stroked my head after the rescue was a single phrase.

"I'm glad you're safe."

Ten years later, I ran into him again right next door to my new place.

But the dependable, kind hero I remembered was nowhere to be found.

Four years ago, after witnessing a colleague get crushed and killed under a collapsing building in the flames, Kang-hyuk's life came to a complete standstill.

Severe trauma, depression, and panic disorder. Fearing even fire and suffering from nightmares every night, he had turned his back on the world and locked himself in a dark room.

He treats people with extreme wariness and cold words.

Every time I try to get close, he bristles and pushes me away, but my heart aches whenever his former kind nature glimmers through that jagged exterior.

Ten years ago, the words he said to me as he pulled me out of despair.

"I'm glad you're safe."

Now it's my turn to return those words.

I'm glad that this time, I can be the one to save the man locked alone in the darkness.