In the fourth season premiere of Bravo's The Real Housewives of Orange County, Tamra Barney, Vicki Gunvalson, Jeana Keough and Lauri Peterson welcome a new housewife to the block, 30-year-old blond bombshell Gretchen Rossi.

In part two of the ladies' Canada trip, Lauri's accusations of Brooks' indiscretions launches the mother of all dinner table debacles. A snowmobile adventure takes a surprising turn, and a subzero vodka binge leaves Tamra tongue-tied. Back in Orange County, Heather guest stars on a new sitcom. Written by Anonymous

Tamra and Simon Barney celebrate their ten-year wedding anniversary with a weekend getaway in Napa, and they invite Vicki and Donn to join them. While Tamra and Simon enjoy a romantic weekend of wine tasting, grape-stomping and gourmet dining, Vicki and Donn struggle just to be nice to each other. Written by Anonymous

While her fiance overnights in the hospital, Gretchen Rossi lifts her spirits by hosting a burlesque party at her home. Vicki Gunvalson and family tour a million dollar yacht that she hopes to buy despite Briana's protests. Vicki, Jeana and Tamra have a girl's night out to get away from the drama in their lives, but a discussion about marriage and ex-husbands turns the situation contentious. Written by Anonymous

All hell breaks loose in Lake Havasu as Jeana Keough, Vicki Gunvalson and Tamra Barney converge on the river for the Fourth of July. The new housewife prepares for her daughter's 18th birthday party, and an incident at her home spray-tan party tests her patience when her daughter has a bratty fit. Written by Anonymous

Gretchen asks Jeff's children to come out from Michigan and rotate visits to their father's bedside, and Vicki faces her fear of needles to accompany Briana to the Red Cross to donate blood. Lynne meets the other housewives for the first time at Orange County's hip new restaurant, but within minutes of arriving, Lynne makes a misstep that leads to some very awkward exchanges. Before the night is over, Tamra and Gretchen square off over Gretchen's treatment of her ailing fianc? - completely derailing their budding friendship. Written by Anonymous

Although Jeff remains in the hospital, Gretchen Rossi still has something to get excited about when her new 5K diamond encrusted engagement ring arrives in the mail. The ladies attend the opening day at Del Mar Racetrack where new housewife, Lynne Curtin, looks forward to getting to know the other housewives better. Drama ensues as Vicki and Tamra snub both Lynne and Gretchen. Written by Anonymous

Vicki Gunvalson visits her family in Chicago and once again tries to get validation from her less than affectionate mother. Gretchen Rossi is taking care of her gravely ill fianc?, Jeff, and reaches the end of her emotional rope. With Simon's urging, Tamra Barney takes an etiquette class and hires a top chef to prepare a formal seven-course dinner for all the housewives, which includes premium tequila tasting. When the tequila shots are served, Tamra and Vicki set Gretchen up for a major fall. Written by Anonymous

With Tamra Barney's formal seven-course dinner winding down, Tamra's son Ryan sees an opportunity to make his move on a very drunk Gretchen Rossi, leaving the rest of the ladies to worry and wonder about Gretchen's well-being. The ladies travel to Santa Monica for a trendy shopping day. Over lunch, when Gretchen confides in the women about her finances, it sparks a heated argument between Lynne and Vicki. Written by Anonymous

Vicki Gunvalson and Jeana Keough take a road trip to Chicago to visit Vicki's friends from high school and former housewife Kimberly Bryant. With Jeff still in the hospital and her future uncertain, Gretchen Rossi looks to secure her financial well being. Lynne Curtin decides to throw a cocktail party for the ladies, where her unruly teenage daughter, Raquel, helps herself to the bar. Written by Anonymous

With her wild 18-year-old daughter, Alexa, running circles around her, Lynne Curtin seeks her mom's advice about how to be a better parent. Vicki Gunvalson comes to a surprising decision regarding the purchase of the million-dollar yacht she so badly wants, and after two grueling months in the hospital undergoing chemotherapy, Gretchen Rossi's fianc?, Jeff, returns home. Later, the housewives blow off some steam with a girls' overnighter in Las Vegas. Written by Anonymous

Jeana Keough and her daughter, Kara, drive to up to Berkley to move Kara into her apartment and find themselves strangers among the bums and hippies. Tamra Barney visits her dad in Iowa and puts it all on the line, spilling her heart out to her estranged father, while Gretchen Rossi does Dallas, reuniting with her four best friends from college. Written by Anonymous

Jeana Keough has her first real date since kicking her ex-husband, Matt, out of the house. Vicki Gunvalson's daughter, Briana, has a new plan for her life that leaves Vicki stunned. It's the end of summer and all the Housewives, past and present, get together. Written by Anonymous

Hosted by Bravo programming executive and Watch What Happens host Andy Cohen, the ladies of Orange County reunite to dish on all drama and give their side of the story on what really went on after the cameras stopped rolling.