In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Q: Stephen:  Robert why do you think they 'll even come looking for us ?
Robert Green: Our friend is a billionaire , you know what happens when you misplace _ one _ ?
A: 
billionaire