There is a Wal-Mart somewhere in Indiana, with a concealed trapdoor in the frozen food section. If you tap on the door three times with your left foot, a voice will ask you for a toll. Open the trap door,''Open the trap door, put three lemons inside, and close the door.After ten seconds, you will hear a knock on the trapdoor and find three Combustile Lemons.And the paper who says:Thanks for choosing Aperture Science Enritchment Center Testing Facility to make Combustile Lemons.NOTE:Don't use the sour lemons, sweet all the way.''