Wales are clear favourites to close in a possible Grand Slam - why, only England's new, makeshift, fragile team stands between them and a potential Grand Slam decider against France in Cardiff next month.
And yet, history hammers at the invader's brain. Wales have won just once in more than 20 years at Twickenham; the headquarters of English rugby has been a graveyard to the hopes of so many Welsh teams.
On paper, Wales should be clear favourites. England, embryonic England, have made four changes from their last game, with new men in Lee Dickson at half back, Ben Morgan at No 8, Geoff Parling at lock and with the mercurial youngster Owen Farrell moved to first five-eighths. Outside him, England have recalled, from the depths of Auckland harbour, Manu Tuilagi to second five-eighths.
Wales have already beaten Ireland and Scotland and there is every reason to believe their greater physicality, composure and class should prevail. And yet, history mocks the clairvoyant.
For me, Wales will prevail. Yet for England's stand-in coach Stuart Lancaster, this is the acid test.
Ireland should comfortably dispose of Italy at Lansdowne Rd, a week before they return to Paris to meet France. By then, the French, too, ought to be closing in on a Grand Slam, for they will surely be too strong for a hitherto disappointing Scotland in Edinburgh on Monday.
On the weekend the Super 15 starts in the Southern Hemisphere, Wales and France should carry the Northern Hemisphere banner with swagger. But there is always the Twickenham factor.
Ireland v Italy
Tomorrow, 2am live ESPN
England v Wales
Tomorrow, 4.30am live ESPN
Scotland v France
Monday, 3.30am live ESPN