David and Leeman perform on America's Got Talent 2014 Semi Finals (VIDEO)

David and Leeman perform on America's Got Talent 9 Semi Finals 1 on Tuesday, August 26, 2014.

This was a strange act, in that it's more predictive magic than an actual trick. But it's actually really entertaining and impressive.

Basically, because they accidentally X'd themselves on their last performance, they decide to do it again to create a do-or-die scenario. They press the X's on Howie, Howard, and Mel B's panels, leaving only Heidi's X untouched. They then offer up five paper bags marked A, B, C, D, and E. One of these bags contains a spike with the final X on the bottom. A crew member placed the X in the bag backstage, so they don't know where the final X is. So each of the judges is going to choose a bag for them to slam down on, and if they choose wrong, not only will they hideously disfigure their hands by impaling themselves, they'll also force Heidi to slam down the final X on her buzzer, eliminating them from the competition. It's pretty amusing, as the guys joke about why no one would ever pick the "D bag," and other such little gags. Howard chooses the D bag (of course), while Howie chooses the A bag (because he's Canadian, "eh!"), Mel B chooses the B bag (naturally), and Nick Cannon picks the C bag. However, David and Leeman give Heidi the choice of keeping Nick's final choice, or switching bags. She chooses to switch, and thankfully, this proves to save the magic duo, as the C bag was the one with the spike in it.

Mel B is impressed, saying that while there's a lot of information to process with this act, she thought they made it very entertaining. Both Howard and Howie enjoyed the routine, with Howard noting that their act is really well-crafted, despite the fact that he's seen this act everywhere lately. Heidi loves their showmanship, and loves that she didn't have to call 911 for them.

But what did you think of David and Leeman?

Watch the performance video below: