### Clue: Finished work? Take on too many! (8)
### Answer: OVERBOOK 
 ### Explanation: Definition: Take on too many
  OVER(finished,done with) + BOOK(a work by an author).
Answer: What airlines and restaurants do, just in case some of the people don't turn up, but when all turn up, you've got an ugly situation – of their own making, I think.