The next day, treemail arrives announcing the immunity challenge. Rob looks determined and interviews that he's not worried about this challenge being "too difficult." He tells Natalie and Ashley that the only thing they have to do is make sure that Andrea doesn't win. He then shows off his new shirt, courtesy of his sister, which has a picture of Amber and his daughter on it. He cut out the picture part and stuck it on the back of his tank top for symbolic purposes.

The contestants arrive at the challenge, where they are confronted by a very large set of stairs. Natalie and Ashley take one look at it and decide not to bother with this one. You can just see it on their faces that they have no intention of trying to win this particular challenge. Probst explains that each contestant will have a lane with three sets of missing steps. They will have to replace those steps with large puzzle piece planks. But they can only take one plank up at a time, and only one plank will fit each opening. Pick the wrong plank, and you've wasted that much more time and energy. Even if every plank you pick is the correct one, you're still doomed to make a lot of trips up and down these stairs. Oh, and it's 110 degrees outside. Basically, this has to be one of the cruelest and physically demanding challenges we've ever seen on this show. Probst says go, and the contestants run to release their first set of pieces. People move quickly in the beginning, since there aren't many stairs to climb at first, and Andrea takes an early lead as the first person to complete the first section. Rob and Grant are right behind her. Phillip and Natalie aren't even trying, really. Rob loses time when he picks the wrong board, giving Andrea more of a lead.

But then, as Rob and Grant start to catch up, Andrea manages to pick the wrong plank and falls behind them. Grant and Rob finish the second set first. Andrea is still in it, though, and Grant makes another mistake as Rob and Andrea put their first planks of the third set in. Grant is wrong again, putting Rob and Andrea two steps ahead of him. Rob, meanwhile, is barely able to stand up. Climbing up and down the stairs in this heat is clearly taking its toll on him. "He is literally carrying his family on his back!" Probst cries. Shut up, Probst. It's just a picture of Rob's family on his back. It probably only weighs a few ounces. And maybe if Rob had kept himself hydrated before the challenge instead of spending his time attaching the picture to his clothes, he wouldn't be having such a hard time now. I mean, Andrea is only a few steps behind him and struggling too, but her body doesn't appear to be giving out like Rob's is.