The sound was broken, but it was him. Her name, pulled from the haze.
Ugh, that's so crushing!
Clark’s hand fumbled toward her hip. “Your lock-picking kit,” he muttered, voice strained. “Check your pocket. Try it.”
NICE! I love a call-back like this!
It was slow at first—lazy, almost delicate—but then it thickened, darkening as it spread across the tile. Acrid. Chemical. Not fire. Something worse.

The cuffs clicked—once. Not open. Not yet.
Oh, no! She's cant' open them!?
The liquid on the floor shimmered again, reacting to the smoke like it recognized it.
This is a horrifying detail.
“That’s not right,” he rasped. “It’s reacting… to me.”
That's seriously terrifying.
“Then we stop it. But not if we die in here.”
Go, Lois!
“When we get out…” Clark began, but a violent cough cut him off, racking his body.
He gritted his teeth, forcing the words through the pain. “I’ll tell you everything. I swear.”

Then the door exploded inward.
That's an intense cliffhanger!
Have to see what happens next!