The ten smokers learn why they are there and are shown video messages from their loved ones who are responsible.

A mountain challenge puts the smokers lungs to the test and adds cash to the growing jackpot. Dr. Will Kirby (""Big Brother 2"") gives everyone a medical examination, but cannot give them all a clean bill of health. A romance develops between two of the housemates, but tensions mount as nicotine withdrawal sets in.

The housemates are taken to a hospital where they get sobering advice from a lifelong smoker who recently had to have her diseased lung removed. Then Tae Bo guru Billy Blanks shows up to give them a physical workout that eases their nicotine withdrawal symptoms somewhat, although not everyone can keep up. Later, a night of partying causes a rift between Danny and Calvin.

A paragliding expedition buoys some of the cast's spirits, but then a psychologist arrives and queries the already irritable bunch about what bugs them most about each other. Then a press conference is held at the mansion and the media frenzy allows the ex-smokers to see themselves on TV for the first time. Finally, one outspoken cast member goes too far and precipitates a crisis.

In a twist, one housemate is given the opportunity to take her share of the money and leave, while a paintball competition against a group of pro-smoking lobbyists unites most of the cast. A visit from Dr. Drew (""Loveline"") gives them helpful advice about addiction and withdrawal, after which they attempt a beach obstacle course.

A gorgeous model who is allowed to smoke moves into the house temporarily, as the housemates try to figure out why she is there. Then they are moved to tears as they receive a batch of letters and care packages from home.

A road trip to Las Vegas brings temptation to the ex-smokers along with a gambling challenge.