The trainers work their final four out at their various local gyms. Ashley says that Jillian has a way of coming in, making her look at what's going on, and forcing her to deal with it. She was struggling initially when she came home, but she doesn't feel that anymore. Jillian truly is magic. Daris, meanwhile, says that he wasn't working out as many hours as he was on the ranch, and hasn't been getting the weight loss that he wanted. Hopefully Jillian can fix that. Bob yells at Mike to show him more, and Michael says he's focused and determined to be in the top two. He forgot how psychotic Bob can be in the gym, but has now been reminded. No sign of Bob working out with Koli -- maybe Koli Bear eschewed his help in his Vegas digs?

With only three more days before heading back to the ranch, Mike says that he's been trying to walk over 20 miles a day. He's really determined to finish the marathon. Ashley worries that going back to the ranch will be shocking, but says she's interested in seeing how much everyone else has lost. Koli is packing and says that he's done everything in his power to be successful. In sad news, Daris has something to show us -- it's a knee brace, resulting from overtraining for the marathon. He really likes to run, he says, and picked up his intensity. It's affected his knees, and now he can't run like he wants to. That, in turn, is messing with his head. His adorable, curly-topped head. Boo!

All the contestants gather together, somewhere close to the ranch. It's a cold and miserable day, which isn't helping anything. Daris tells us that eight people have run a marathon over the past two seasons. The best time so far belongs to Tara at four hours and fifty-five minutes. He thinks he can beat it, good knee or no. Ashley is focused on staying positive. She starts off with noting that at least it won't be hot. Sami greets the contestants and acknowledges that it's effing cold and rainy. However, a challenge is a challenge, and they each have $10,000 for charity on the line.

The marathon begins! Daris and Koli take off, while Mike and Ashley follow behind at their own pace. Daris tells us that running a marathon has been a goal of his since starting the show, and he wants to do the best that he can. Koli tells us that mere months ago he was sitting on the couch, and now he's running a marathon. This is proof to all of us that it's in our grasp to do the same thing, and there are no excuses. And then, happiness. The sun comes out. Koli struggles a bit on some of the uphill parts of the course around mile five, but encourages himself through it and never stops running. Mike and Ashley run slowly together, and are pretty adorable while doing so. They're clearly psyched to be out there, and to have each other's company. Ashley tells us that she's the girl she always wanted to be -- really, truly happy. Five months ago, Mike weighed well over 500 pounds. His daily routine consisted of sloth, and sweating like hell just from walking up the stairs. Now, he's run/walking a marathon and feels damn good about himself.