The lovely smile on the face of Martina Hingis is the smile of the tiger - and her prey had better be warned that when she lights her sweet face with the sparkle of that toothy expanse it really means she is ready for the kill.
Although the Wimbledon women's singles draw looks the most wide open for years, the 'Swiss Miss', who was destined to be a tennis superstar almost from the cradle, goes in as firm favourite to lift the crown for a second time despite the fact that she has not won a Grand Slam title since the Australian Open in January 1999.
The time-lapse will have merely increased her appetite for another taste of the major honours which by now has surely become the staple diet that feeds her career.
And the natural pride of a born champion will also be stung into action by the fact that she is returning to the arena where, 12 months ago her defence of the title was embarrassingly obliterated in the first round by 17-year-old Australian-Serb qualifier Jelena Dokic.
Dokic's subsequent progress to the last eight went some way to making an alibi for Hingis' dismal exit but there were more reasons than that.
Although she will leave her teenaged years behind her in September, Hingis still leans heavily on the encouragement and expertise of her mother and coach Melanie who last year decided not to accompany her to London.
This is the woman who, having named her daughter after the great Navratilova, spotted such an unmistakable potential in Martina even at the age of eight when they still lived in the old Czechoslovakia that she moved them to another country and dedicated her life to grooming her protege to stardom.
Without Melanie for the first time on active tennis duty, Martina soon felt exposed, uncertain of how to deal with routine problems off court, and vulnerable. Most of all she missed the coach who knows her athletic strengths and weaknesses inside out.
Now, though, Hingis not only has mum back in her corner but also a new boyfriend in Swedish star Magnus Norman whose upsurge of form this year makes him one of the contenders for the men's title.
And she has had a steady, almost low-profile build-up to Wimbledon since winning back the affection of the French fans with her stately progress to the semi finals at Roland Garros a year after throwing an almost unforgivable tantrum - serving the last point underarm and then stomping off court - when losing an emotional final she had virtually tossed way to Steffi Graf.
Hingis decided not to take part in the traditional grasscourt curtain-raiser to the All-England Championships at Eastbourne.
And that may well have turned out to be a great decision as the wind and rain on the South East coast caused all sorts of problems for major players like reigning Wimbledon champion Lindsay Davenport, veteran French star Nathalie Tauziat, talented South African Amanda Coetzer and young pretender Anna Kournikova.
They all probably ended up with more questions than answers about their Wimbledon prospects after a bizarre tournament which was eventually won by 30-year-old French number four Julie Halard-Decugis in a damp, wind-swept, unlikely final against Belgium's Dominique van Roost.
Meanwhile Hingis ended up with yet another trophy in her locker after being handed the Heineken Trophy in Holland on Saturday, content to feel well rested and with a little more grasscourt acclimatisation after winning the Rosmalen tournament at a canter.
Given a bye in the first round, she had to play just two matches - one of them lasting just 36 minutes and the other a straight sets stroll against out-of-form American Jennifer Capriati - to reach the final where Romanian rival Ruxandra Dragomir gave up injured when trailing 6-3 3-0.
So Hingis is settled and seemingly content again. She is not the sweet, outgoing little girl we saw lift her first Grand Slam trophy aged 15 at Wimbledon in the women's doubles with Helena Sukova back in 1996 but there's still a basic brightness and bounce about her that promises many more glories to come.
A year after that Wimbledon doubles success she was back winning the singles crown and now five more Grand Slam triumphs, plus 21 other title wins on the women's tour, have inevitably brought a tougher, sharper edge to her personality.
The smile will still be there, though, and as ever it will even be reproduced in times of on-court stress to mask those moments of uncertainty that even a champion occasionally feels.
That's when the opposition ought to know that Hingis is at her most dangerous.
The smile really says: 'OK, that's your best shot and it hurt me - but now let's see how you deal with what is coming back."'
In those moments it is worth looking into the eyes of Martina Hingis and discovering that they are ice-cold, completely focused on the business in hand, the complete antithesis of that glowing smile - and a warning sign that should not be ignored.