In this amazing trick, David Blaine takes an ice pick and stabs it through his hand so it looks out at the other side. He then asks Neil deGrasse Tyson to pull it out. After Neil pulls the icepick out of Blaine's hand, there is no blood and the hand seems to be completely fine.
Neil deGrasse Tyson and Pharrel are both amazed!
You can see this mindblowing illusion here:
Blaine has what is called a fistula through his hand. A fistula is a 'corridor' made out of scar tissue, which can be penetrated by the ice pick without causing any blood or other visible injury. Blaine probably created this fistula in his hand by repeatedly causing small injuries in the same direction, producing more scarr tisue every time until there was a full path of scar tissue from one side of his hand to the other.
The ice pick can then pass through this scar tissue without causing any visible damage at all. In a way, this is not really a trick, since the ice pick actually went through his hand. It turns out Neil deGrass Tyson was right!
For a more detailed explanation of the fistula and some historic examples, you can read our explanation of the Ricky Gervais trick.