It was 20 minutes that shook Emirates Stadium. On March 31, 2010, Barcelona arrived in North London and tore Arsenal to shreds in the opening exchanges of the clubs' Champions League quarter-final, first leg. Lionel Messi, Xavi, Sergi Busquets and Pedro demolished the home defence, and though Arsenal withstood their barrage, superiority was emphatically established. It is that passage of play, perhaps more so than Lionel Messi's subsequent four goals at Camp Nou, that will be weighing heavily on Arsene Wenger's mind on Friday.
Though the Arsenal manager bravely welcomed the possibility, and seeming inevitability, of drawing Barca for the second season in succession prior to the draw in Nyon, when fates aligned and balls were draw in the Swiss town, thoughts immediately drifted to that savaging in March. No team has ever taken Arsenal apart in such style under Arsene Wenger. Not with that audaciousness, not with that speed and not with that ability.
It was, as Pep Guardiola said at the time, "the best 45 minutes since I became a coach". Quite a claim from a man who deals in consistently brilliant performances, and after a half that somehow finished 0-0.
Arsenal's subsequent comeback from 2-0 down only obscured what was a masterclass from Barca. Nicklas Bendtner's opening goal at Camp Nou also created false hope. Instead it was Messi's four goals that finally demonstrated the evident chasm in class between the teams.
Of course, Arsenal's history with Barcelona extends beyond last season, and it does not make favourable reading for those in North London. In 2006, following Jens Lehmann's dismissal and Sol Campbell's opening goal, Barca reigned supreme in the final in Paris. It is fair to say that Arsenal have a score to settle.
But are they capable of doing so? Jose Mourinho and Inter demonstrated that the way to eliminate Barcelona from European competition is to go firmly on the defensive. Mourinho even insisted following that semi-final win for the Nerazzurri that he was happy for his side to cede possession and remain firmly couched in retreat. Arsenal, as they have amply demonstrated in recent seasons, are simply not cut out for that kind of approach.
With players such as Samir Nasri, Jack Wilshere and, of course, Barca's summer transfer target, Cesc Fabregas, Arsenal also play the possession game. Alex Song is no Esteban Cambiasso, who so effectively dealt with his countryman Messi, and Arsenal cannot and will not be happy to allow Barca possession while sitting back and parking the bus. It is hard to escape the feeling that they will be made to pay for this admittedly admirable philosophy.
The bookmakers agree. Having been priced at 14/1 prior to the draw, Arsenal went out to 22/1, while Tottenham, due to face Milan, are at 20/1. Tottenham at shorter odds to win the Champions League than their local rivals? That is a unique moment in the history of Wenger's reign, and not one to brag about.
This game will be rightly painted as a clash between two great footballing sides, the youthful excellence of Guardiola versus the experience and wisdom of Wenger, but one issue of course dominates in the Catalan press. Mundo Deportivo's website lead with the headline 'Cesc back!' while Sport's variation on a now well-established theme was 'The return of Arsenal and Cesc'.
The graduate of La Masia, a former contemporary of Gerard Pique and Lionel Messi, who idolised Pep Guardiola as a child and who plays alongside Busquets, Xavi and Andres Iniesta in Spain's all-conquering side, was denied a return to his boyhood club this summer by Wenger and in their performances in the league and Europe this season, Arsenal have shown little inclination to convince their captain that his hunger for trophies can be sated in Islington, rather than Catalunya. It would not be a surprise to see the Barcelona-based press remind him of that in the build-up to the second-round tie.
Of course, Arsenal and their captain should not even be in the position where they are nervously awaiting a trip to Camp Nou. Having won their opening three games in the group, against Braga, Partizan Belgrade and Shakhtar Donetsk, they should have cantered into first place, rather than limping into second. That carelessness, brought about by suspect defending, may have proved fatal.
Certainly when Wenger casts his eyes across the draw and sees Manchester United placed with Marseille and Chelsea drawn to face FC Copenhagen, the prospect of a visit to Camp Nou at this stage will surely fill him with dread. Tottenham have a much sterner test in Serie A leaders Milan, despite topping their group ahead of Inter, but the Rossoneri are not Barcelona. In fact, no one is.
Arsenal know that better than most after being dismantled by Pep Guardiola's side last season. With Barcelona arguably better than ever having produced an era-defining display in beating Real Madrid 5-0, and Arsenal showing few signs of progress over the past eight months, a repeat of that magical 20-minute spell, and the elimination that followed, must surely be feared.