Amelia Earhart is flying solo across the Pacific Ocean when something horrific happens. The American looks into the camera and screams "Oh no, my period!" before losing control of her aircraft and dropping into the ocean. Never to be seen again.
It did not happen in real life, of course, but is a scene in the American sitcom 30 Rock. And writer Tina Fey is not mocking Earhart's disappearance in 1937, which led to the first female aviator to fly solo across the Atlantic being declared dead 'in absentia', but is poking fun at the effect menstruation is perceived to have on women.
But has what many describe as 'the last taboo' now been broken?
Britain's number one tennis player Heather Watson blamed "girl things" on her first-round defeat at the Australian Open this week and ever since there has been non-stop chatter about monthly cycles, stomach cramps and their impact on professional athletes.
Are periods a problem for elite sportswomen? Does it affect performance? We talk to women's marathon record holder Paula Radcliffe, Baroness Tanni Grey-Thompson, physiologist, Professor John Brewer, and gymnastics coach Helen Potter.
A major impediment or a minor snag? - "I broke a world record so it can't be a hindrance"
British middle-distance runner Jessica Judd says her running times can vary by 15 seconds depending on what stage she is at in her cycle.
"I ran 3000m at the national championships in 9 minutes 15 seconds and felt really tired," explains the 20-year-old. "One week later, at the Birmingham Grand Prix, I ran the same distance in nine minutes flat with no extra training. It's scary that it can affect you so much because it is the difference between first and last."
But not everyone suffers the same. On the morning of Sunday, 13 October, 2002, Paula Radcliffe's period started. Late and inconvenient. It was the day the Briton was to line up for the Chicago Marathon. It was the day she went on to break the world record.
"I tried to put it out of my head and not let it become an issue," recalls the former marathon world champion. "It's one of those things that can become a bigger issue if you let it.
"I broke the world record so it can't be that much of a hindrance, but undoubtedly that's why I had a cramped stomach in the final third of the race and didn't feel as comfortable as I could've done."
A simple solution or an added headache? - "There's not an easy answer to dealing with it"
Former world badminton champion Gail Emms used to take the contraceptive pill to control when her period would occur, while Baroness Tanni Grey-Thompson, the most successful athlete in Paralympic history, tried contraceptive injections to stop her periods.
Paula Radcliffe would take the pill for three weeks at the start of her season to change the timing of her periods, ensuring they did not fall during a major championship or a big race, but there isn't a one-pill-fits-all solution.
"I got light periods so I probably only got eight a year so it wasn't that much of a problem," explains Baroness Grey-Thompson.
"I didn't want to be on the pill because, depending on what you're on, it can cause problems with water retention. I did have injections twice to stop my periods, but you have to them every three months and if you're not in the right place to have them it can be a nightmare to try to balance."
Emms believes Watson should have been better organised: "As an athlete my body has to be in the best condition it can be to perform and if that means sorting out my period, it means sorting out my period."
But former British number one Anne Keothavong does not believe it is so easy for a tennis player to "meddle with Mother Nature".
"As a tennis player, there's a tournament going on virtually every week of the year, it's a long season," Keothavong reasons.
No research and no understanding - "More studies need to be done"
"The impact periods have on different athletes is an area which needs to be addressed," says Dr Richard Burden, senior physiologist at the English Institute of Sport. "In elite sport, the research in that area is quite limited."
Knowing Jessica Judd was due to be on her period on the day of the 800m heats at the World Championships in Moscow in 2013, doctors prescribed the then teenager with norethisterone, a hormonal tablet which delays menstruation.
The 18-year-old finished a disappointing fifth and failed to qualify for the semi-finals. A distraught Judd could be seen crying on the track. The medics "screwed up" says Paula Radcliffe.
"They gave her the wrong thing," explains Radcliffe. "I knew from experience that norethisterone made things a 100 times worse, Jo Pavey knew that, others knew that, but it seems that nobody within British Athletics had written that information down.
"They tried it because that's what medical science was saying you should do in that situation. After that I intervened and told them not to give it to Jess, or any other young athletes, and advised Jess on what I used to do.
"Doctors in sport are often men and they don't understand. You need more women who understand to give more evidence, have more studies done, because it's only a small group of elite sportswomen who have tried to do things to control their period."
British Athletics says it is addressing this, and has recently introduced a number of initiatives - although it admits improvements can still be made.
It told BBC Sport its medical staff were "very much aware of the added challenges concerning menstrual issues around performance athletes".
"Each case is looked at individually and it is the aim that any particular strategy is trialled well in advance of competition," it added.
Some talk, others hurt in silence - "I wouldn't have talked about this a couple of years ago"
How an athlete prepares for a big competition during her period can not only affect performance but relationships within a team.
"The girls would train together, you'd learn things from other girls," says Gail Emms.
|Myths, magic and menstruation|
|It has been said that from first-century Rome to the 19th-century England, menstruation was thought to leave women periodically dangerous.||As late as 1878, the British Medical Journal printed the opinions of physicians who believed that menstruating women could cause bacon to become rancid.|
"One girl I know, she didn't take medication but knew she was going to be on her period during a big competition and they ended up losing when they should have won and her partner, a male partner, is still fuming about something that happened years ago."
But not everyone finds it as easy to talk about such personal matters as Britain's elite badminton players. "I don't remember it being talked about in my sport," says Baroness Tanni Grey-Thompson.
"I probably wouldn't have talked about this a couple of years ago, but it should be a massive challenge for sports to talk about it with teenage girls. How a young 13-year-old sportswoman handles it could encourage or discourage them from being sporty."
'Girl problems', 'The Curse' - "Clouded by euphemism and wrapped up in myth"
Women are likely to bleed for between 2,250 to 3,000-plus days across their lifetimes and a study in 2010 revealed girls were reaching puberty ever more prematurely, so why is menstruation not discussed in the majority of cultures?
"One of the things I was fascinated by was how many euphemisms there are about this topic, which is an indication of how much of a taboo it is," says Karen Houppert, author of The Curse: Confronting the Last Unmentionable Taboo, Menstruation.
Companies have been advertising tampons since the 1920s but it has always been done with discretion - never during the Super Bowl, or on the front pages of a newspaper.
"It's still narrowly advertised, and there are still veiled references to what's going on," adds Houppert.
"Watson said 'girl thing' which is vague. It could have been something else, but we presume it's her period. Periods are wrapped up in myth and magic and sexuality."
Sluggish, fatigued and injury prone? "Tendons and ligaments become lax and elastic"
In 2009, Anne Keothavong became the first British woman in 16 years to be ranked inside the world's top 50 but hers was a career troubled by knee injuries sustained when she was menstruating.
"It does affect you, there's no doubt about it. I had ACL injuries on both knees and both times when I fell over it was that time of the month," says the 31-year-old.
"It does affect your co-ordination and every female athlete performing at a high level will be aware of that but it's not spoken about because, I guess, men don't want to hear about it and it's quite a personal thing.
"It's personal to every athlete and by no means should it ever be used as an excuse but, at the same time, it does have an effect."
John Brewer, professor of applied sport science at St Mary's University, says there is evidence to suggest women could be more susceptible to injury at different points of their monthly cycle.
"There's an issue that you might be slightly prone to injury because oestrogen is at peak level around the time of ovulation and that causes the tendons and ligaments to become lax and elastic," he explains.
Iron deficient, hot and bothered - "The impact isn't as great as people think"
In the Melbourne heat, Watson's head felt dizzy and her energy had been sapped. She had no fight left. But can menstruation ever really be blamed for a poor performance?
"There's no conclusive evidence that it has a massive impact on performance but, at the same time, anecdotal evidence would suggest if you lose a significant amount of iron and you become anaemic your endurance performance will suffer," explains Professor John Brewer.
"That aerobic fitness isn't just important in marathon-type sports, it's also an important component of sports like tennis, football and hockey, where you have to sustain a high work rate for quite a long period of time."
During her period a female athlete could suffer when conditions are hot and humid because hormonal imbalance can cause the body's core temperature to slightly rise. But there are solutions. Hydrating before and during exercise, and drinking sodium-based electrolyte drinks to make sure the fluid is absorbed, will lessen the impact of the heat.
"Because Heather Watson has alluded to it as one of the reasons why she didn't perform, there's a danger of it being blown out of proportion slightly," adds Dr Richard Burden. "It happens to all female athletes, but you don't often hear about the negative consequences of it."
The coach - "You have to have empathy and know how they're feeling emotionally"
Planning to conquer the sporting world requires more coaching nous than merely ensuring an athlete is physically ready to be faster, stronger and better than everyone else.
Helen Potter, coach of gymnast Claudia Fragapane who last summer became the most successful English gymnast at a Commonwealth Games for 84 years, believes a great coach is a communicator and empathiser, someone who can build an irrepressible mind. Only an athlete at ease with herself and her 'invisible troubles' has the bombast to flip and twist to glory.
"The mind is very important, people forget we're still animals," says Potter. "You do adapt your training depending on what part of the cycle your young gymnast is in, but they've got to learn to be able to cope with whatever time of the month it is.
"You have a training plan, a detailed plan of training cycles leading to major competitions but we are dealing with human beings, and emotional human beings, so you have to adapt in subtle ways, practice things which are tried and tested, rather than try something new."
Should Watson have blamed 'girl things'? "Her bringing it up is a double-edged sword"
Since Watson's revelation in Australia, many males and females have been seen shuffling uneasily in their seat, red of cheek, and uncertain of eye, at the mention of the female menstrual cycle.
But has discussing the subject helped gain a greater understanding of what women, and elite female sportswomen in particular, have to endure on a monthly basis?
"Her bringing it up is a double-edged sword," says Karen Houppert.
"Using it to explain a less than stellar performance can be a problem for women. Does it mean a female heart surgeon is less capable for one week a month?
"At the turn of the last century there were all sorts of reasons given why women should stay at home and part of that was the issue of menstruation.
"The positive is that she did raise the topic. It helps that a young girl mentions this is going on. It's good when it surfaces in conversation, otherwise it feels that part of your reality doesn't exist and to acknowledge its existence is a very good thing."