Tennis Women's final: The film crew which shot a scene on Centre Court last week opted for a barely credible storyline: a Brit wins the championship.

Had they looked around, they would have noticed the Williams clan and a ready-made script. Younger sister Serena helps a panicking older sister, Venus, through semi-final against Belgian opponent. Older sister gets injured in the effort and must then face younger sister in the final. But the Injured One has not beaten the Younger One in the last five meetings. The Younger One is the world number one, a winner of four Grand Slams from the last five, and she knows Injured One may not hold up.

Flush out the storylines. Will the abdominal injury to Venus force her to default during the match? Will Serena's sympathy for her older sister scramble her game plan? Deep down, does Serena want to lose? Is the injury to Venus worse or better than she has said? How do sisters, doubles partners, close friends, prepare to beat each other? Will the parents, Richard and Oracene, become involved?

The Williams sisters meeting in a Grand Slam final is obviously a serial tale. At the Australian Open in January Serena won in three sets. At last year's US Open Serena won in two sets. Wimbledon last year was no different and it was Serena again, 7-6, 6-3. The French Open in 2002 and again the younger sister emerged as champion after two sets.

Their blazing trail across the tennis firmament began with Venus winning the first three Grand Slam finals from the Australian Open in 1998 to Wimbledon 2000 and the US Open in 2001. But from the French Open last year Serena has been unstoppable.

The dent Justine Henin-Hardenne made on the family monopoly in Paris this year has not been sustained on the grass, and the spectacle of Venus in full flight on Centre Court against Kim Clijsters was a throwback to when she once dominated the world.

But with her abdomen heavily strapped and her movement limited, today's final has the makings of a rout as well as a drama - although the sisters tend not to do that to each other.

"As a rule I never play with pain," said Venus after her semi-final with Clijsters. "I generally retire immediately. I've never been taught to play with pain. My parents always told us to put the racquet in the bag, go off the court."

Unable to practice properly and unlikely to even attempt overheads or full-out serves, Venus has been given a particularly difficult physical task. The bizarre thing is that, because of their close relationship, it is her opponent who probably knows most about the extent of the injury.

"Basically I got a tape job," said Venus, talking about what the medical staff did to get her back on court after the rain break on Thursday. "They looked at me all over to see if I was compensating somewhere else. They wrapped me real tight. I think that helped," she said. "I just kept telling myself, 'Venus, do what you do in practice. If you win, lose, draw, fall off, fall down, whatever, just do what I was taught to do'."

It's been suggested that for Venus to start beating Serena again she would be better to break away: get a different practice partner and even a new coach. Serena disagrees.

"I think in this tournament Venus has been playing the best and I've had to raise my level of play to be able to compete with her. As far as a separation and getting a different coach, I wouldn't change anything that's been working. Old saying, if it's not broke, you shouldn't really fix it. I don't think there's any problems."

It is the fifth time in Wimbledon history that sisters have met in the singles. Britain's Maud Watson defeated Lilian in the inaugural championship in 1884; Australian Gail Sherriff-Chanfreau beat Carol in the second round in 1966, while Venus has played Serena twice, in last year's final and the 2000 semi-finals.

The odd thing in this theatre is that the greatest words of encouragement and comfort for Venus have come from Serena. While she has beaten her consistently over the past year, it is Serena who points out that things don't always remain the same.

"Actually, Chris Evert beat Martina Navratilova many times in a row, but then it changed. It's her getting used to my game," said Serena.

Clearly this sister act is far from over.