It basically writes itself.
Cave Johnson : Those of you who volunteered to be injected with praying mantis DNA, I've got some good news and some bad news. Bad news is we're postponing those tests indefinitely. Good news is we've got a much better test for you: fighting an army of mantis men. Pick up a rifle and follow the yellow line. You'll know when the test starts.
Interesting, let's see what others think.
This has 0% relation to the storyteller