1. Don't go on unless you've translated the garbled announcement.
2. Don't go on until you've figured out what's going on with the glass case and switch and keyboard.
3. You are at a Vogon Poetry Appreciation Session. The Vogon Captain is about to read you his favorite poem. The Guide's entry on Vogon Poetry makes clear that this is extremely nasty.
4. Because you have already flipped the switch on the glass case and listened to the recording, you know that you'll have to listen to the second verse of the poem in order to get the atomic vector plotter.
