Ross and Rachel have split up, and Phoebe, Joey, Chandler and Monica are forced to choose between them. Chandler in particular is struggling with the break-up as it reminds him of his parents traumatic divorce, so he begins smoking again. Things worsen when Rachel's sister invites the gang on a ski trip, and they are forced to leave Ross behind. With the others gone, Ross gatecrashes Carol and Susan's anniversary dinner. But disaster strikes when the gang are left stranded in the middle of nowhere.