The #WhyWait Invent-Off teams have their work cut out for them. Just when they thought they’d gotten past all the major hurdles and could breathe a little easier, Episode 4 is here to make the competition, and their creations, more interesting.

The eleventh-hour challenge they’re faced with: incorporating a mystery item into the inventions. The item in question — chosen by fans back in Episode 2 — is a near field communication board, which the teams will need to use to bring another level of security to the designs they thought had already been hammered out.

To see how they handle the challenge, check out the fourth episode now. (If you need to refresh your memory on what’s happened so far, check out episodes One, Two, and Three.)

This post is a sponsored collaboration between Qualcomm and Studio@Gawker.