Shannen Doherty Hoping to borrow a successful move from the network’s old playbook, Fox is welcoming back former "Beverly Hills, 90210" good girl Shannen Doherty as a "North Shore" bad girl.

Doherty, who recently left her gig hosting the SCI-FI Channel’s "Scare Tactics," will begin a multi-episode story arc Sept. 20. The former "Charmed" star will play Alexandra Hudson, the illegitimate daughter of hotel magnate Walter Booth (Christopher McDonald). Alexandra is sure to stir up tons of trouble with newfound sister Nicole (Brooke Burns) as soon as she hits the beaches at the Grand Waimea.

Fox hopes that Doherty’s arrival will goose the somewhat stagnant ratings for the sun-soaked summer soap opera, following in the footsteps of Heather Locklear’s successful addition during the lackluster early days of "Melrose Place."

Through its first six episodes, "North Shore" is pulling in an average of 4.63 million viewers per week. Fox has ordered extra scripts beyond the show’s initial 13-episode order, but the network isn’t ready to commit to additional episodes.

The possibility of Doherty’s continued role on the show could provide incentive for Fox to extend the "North Shore" run.

However, for every successful Locklear injection, there have been at least as many fizzled experiments, such as WB’s unsuccessful attempt to welcome Carmen Electra to "Hyperion Bay" in 1999.

Fox already had mixed results earlier this year when "Beverly Hills, 90210" good guy Jason Priestley became a "Tru Calling" bad boy. Priestley’s arrival had little effect on that show’s ratings, but his presence reportedly gave the show a creative boost and helped to score a second-season renewal.