Very exciting stuff told in a stolid sort of style that works well. The second to last paragraph ends in a very awkward sentence that I couldn’t entirely follow. Great job setting up not just the immediate story but the reason for their being there and additional urgency of the situation.

Reminds me of Gary Paulsen’s books. :) (you left out the word plane in second to last paragraph)
I am reading on…

tiny criticism – what did not work for me was: “a virus…had decided to spread” i would have written “a virus…was spreading”. the scene is set. lets read on.