How to Save a Terrible Job Interview

You’ve done all the prep work for your job interview: rehearsed, brainstormed questions and prepared your answers, planned your itinerary in order to be on time, and gathered your portfolio in case the interviewer asks to see it. By your own high standards, you think you are ready to ace it, but there are still times when you end up with a catastrophic interview, anyway. What can you do to salvage the situation before it becomes a lost cause?