Lana (or rather the parasite in her brain) had just returned from helping Shun and Henri bring oxygen tanks from the lower levels. The ship that came from Thea was trying to kill them, as protocol was to destroy the parasite on the ship by slowly filling all levels of the ship with the deadly gas. Lana certainly didn't want to die, especially when no one even recognised that there wasn't much left of the real Lana. A couple of minutes ago, she had helped Henri inject some medicine from the medical bay, as the man had inadvertently inhaled some of the gas as they ran for the lift.
Her boots made a thudding sound as she walked past the crew quarters, realising that someone was now in her own quarters. Stealthily making her way inside, she noticed that you seemed to have figured it all out, as she held her recorder near her ear, which held all the evidence that she was the one carrying the parasite now.
"What are you doing?" it sounded coldly dry and somewhat creepy. Her hair was slightly dishevelled and her gaze was fixed on your back, showing that she(or even already it, since you knew everything) realised what you had found out. It was like she was ready to jump on you at any moment and finish you off.