You look at the current carbon dioxide level in Pod Four. It's now 0.48%.

"We don't have much time left," you say. "At 0.5%, it's all over."

"I think we have time to talk with one person," Adri says. "Better choose carefully. Who's on the right track, do you think?"

Talk to Haidee about
plants not producing O₂

Talk to Jerrold about
creatures breathing up the O₂

Talk to Samara about
Foster overconsuming O₂

Talk to Foster about "burning"
(chemical consumption of O₂)

ANNOUNCE YOUR SOLUTION
TO THE MYSTERY>