Expect the unexpected.
You've spent loads of time writing and rehearsing the perfect show- and then IN THE MIDDLE OF YOUR PERFORMANCE something throws a monkey wrench into the works!
This does not have to spell disaster for you, if you are prepared for the unexpected.
The key is simple.
Have a number of well-rehearsed routines ready to go, props on the table, just in case.
Don't miss a beat. Grab and go!
And sometimes your show will be even better when you can smoothly change gears...