Joining David's team this week are comedic TV presenter Patrick Kielty and veteran actor Bernard Cribbins. They'll be doing their best to outwit Lee and his team: Deborah Meaden from Dragon's Den and comic Mark Watson. Did Patrick Kielty once punch Muhammad Ali in the face? As a child, did David Mitchell have a special way of communicating with Captain Kirk during Star Trek? And did Bernard Cribbins once sell his wife's car and then pretend that it had been stolen?