12/02/2011 12:17 pm ET | Updated Feb 01, 2012

Tom Cruise's Insane Moves For 'Mission: Impossible IV - Ghost Protocol': How He Did Them (VIDEO)

We've spent months hearing about -- and through trailers, seeing glimpses of -- Tom Cruise's insane vertical grappling up the side of the Burj Khalifa building in Dubai.

Now, we finally get to learn how he actually pulled them off.

In this new video for ET Online, Cruise and the rest of his "Mission: Impossible IV - Ghost Protocol" co-stars discuss the crazy climbing, amongst a number of other topics. Cruise trained for months, running up and down vertical walls to get his stamina built up for his big scenes. Meanwhile, Paula Patton prayed that he'd be okay on filming days -- and Jeremy Renner, as he said last week, nearly puked.