Magician has a marker pen. A spectator is asked to draw something using the Chisel tip, but cannot draw anything because the tip has dried out. Magician tries to draw something using the Bullet tip, but only finds out that the Bullet tip has also dried out. Strangely enough, magician says, "The both tips are not usable. That means, the battery has run out." Inside the marker pen, there sure is a battery. The magician replaces the old battery with a new battery.After that, both of the Chisel and Bullet tips become usable. Great joke for Ambitious Card routines.