If looks could kill, you would want to store the one that Arsene Wenger directed at Robin van Persie in a well-secured gun rack.
It was a late February afternoon and the then Premier League champions were playing Southampton.
But Arsenal were beginning to realise they would not be calling themselves title-holders for much longer.
The marvellous unbeaten run that had helped propel the London club to the last of their English crowns was history.
They were becoming hotheaded with frustration at their declining status. That 2005 day at Southampton would be a turning point in young Van Persie's career.
He had joined Arsenal the previous summer for a bargain €3 million (Dh15.3m) from Feyenoord in his native Holland and had not quite shaken off a reputation for indiscipline.
He was only 21 years old and in the first half of the 1-1 draw with the home team, he had planted his forearm, hard, into the face of Rory Delap. He was booked.
"The mood was ... well, there had been a lot of fouls," said Robert Pires, one of the so-called "Invicibles" and part of the Arsenal team that day, too.
"But Southampton had had a player sent off and we had a 1-0 lead. When we went in at half time, the manager told us it was important to stay calm and, specifically, not to pick up any reds."
Six minutes after the interval, Van Persie hurled himself at Southampton's Graeme Le Saux and was dismissed. It was on the way to the dressing room that Wenger gave the young Dutchman his killer glare.
Fast forward six and half years, and Van Persie wears Arsenal's captain's armband, given to him by Wenger for perhaps the most important leadership challenge the club has faced since the heady, long-gone days of "The Invincibles".
Wenger no longer burns with anger at the fiery temper of his best striker, but says of him, ahead of tonight's Champions League meeting with Marseille: "He's on fire."
The last team spectacularly singed were Chelsea, in an extraordinary London derby last Saturday. Van Persie scored three of Arsenal's goals in a 5-3 away victory. He now has 28 goals from his last 27 league matches.
In between his big sin against the Saints and the crest of form he now rides, Van Persie has matured and developed.
"Technically, he's one of the best footballers I have known," said Pires, who spent two years alongside Van Persie in Arsenal's attack.
"He was always by far the most powerful striker of the ball there - it really is incredible how much force he generates. He has always had perseverance. He takes ideas on, understands how to make himself better. That's behind his maturing so much."
In full flight, on the ball, taking on defenders, there is a touch of the artist about Van Persie. He often gets asked if that might be in the genes. Both his parents were creative, his father a sculptor, his mother a designer of jewellery.
His youth included episodes of naughtiness at school, he would later acknowledge, and his burgeoning youth career in Rotterdam, where he grew up, also featured confrontations.
He was among Feyenoord reserve players attacked by fans of the Rotterdam club's Amsterdam rivals Ajax in a notorious incident in 2003.
He had been with the reserves because the then Feyenoord head coach Bert Van Marwijk had demoted him after a falling out.
Like Wenger, Van Marwijk would later acknowledge and profit from Van Persie's growing up. Together, as Dutch national coach and Holland striker, Van Marwijk and Van Persie would reach a World Cup final last year. By then Van Marwijk had decided Van Persie was best utilised not from a wide position but as a central striker.
"He's a different sort of centre-forward," Wenger said. For his country, that role still generates some doubts. He contributed only one Dutch goal during the World Cup.
He then suffered an ankle injury that kept him out of the Arsenal team for two months. Once he returned, it was to an Arsenal approaching a crossroads. Cesc Fabregas, his predecessor as captain, was lobbying to join Barcelona; Samir Nasri was paving the way to join Manchester City. Van Persie took on the role of senior professional at a club in transition.
Van Persie has given them a momentum to climb out of it.
"He has calm, experience and above all top quality," Wenger said after Saturday's blitz at Stamford Bridge.
"Maybe he is at the right age, now, too. At 28 you analyse situations quickly."
The looks Van Persie now gets from his boss are all admiring.
sports@thenational.ae