Whipping up a properly-constituted hockey animosity requires a few staple ingredients, among them high stakes, repeated confrontation and anger.
It always helps to have a heightened sense of grievance to make the mixture coalesce, and by that standard, the heat is building up nicely under the burbling vessel in which the Montreal Canadiens and New York Rangers find themselves.
While the Habs' Brandon Prust was preparing for a meeting with the league's disciplinary department on Friday, the victim of his late, blind-side hit in Game 3 of the Eastern Conference final, Derek Stepan, was meeting with doctors to deal with what the Rangers revealed is a broken jaw.
That the Rangers would be so forthcoming about the exact nature of an injury at a time in the season when teams are at their most secretive can't have been a coincidence; on the Friday evening the verdict was delivered, Prust was suspended for the next two games of the series.
And if anyone needed further proof that the Stanley Cup playoffs are no place for nurturing sentiment, Prust and Stepan are friendly and used to play together on Broadway.
The mystery of divining human intent remains intact – despite centuries of scholarship aimed at prying it apart – but Rangers coach Alain Vigneault had a pretty good idea of what Prust was trying to accomplish.
Speaking in French at a news conference, he said "I wouldn't want any of my players to do what Prust did, which is to hurt an opposing player.
"He's the one who openly mentioned what [Chris] Kreider did, and other than a few over-zealous fans, 95 per cent of the people in hockey knew Kreider didn't want to hurt [Montreal goalie Carey] Price [in Game 1]," he said. "But what Prust did, by being late with the check, up toward the head, we're going to leave it at that."
The Habs weren't surprised at Vigneault's veiled inference that the hit was deliberate– the tone will have been familiar given they struck it earlier in the series when Price went down.
"It's the usual war of words; things happen really quickly in a game, but I think all Prust was trying to do was set a tone, and that's what he did," centre David Desharnais said.
Hockey players are greedy consumers of emotional fuel, and in a series that has already had its share of rallying points– the funeral of Rangers winger Martin St. Louis's mother, the injury to Price, and now this – the hit on Stepan has the feel of another pivot point.
"There have been losses on both sides; everybody's debating what's intentional, what's not intentional. Whether or not it is, it builds something up. You know you're going to face the same team a couple more times, so yeah, it builds that hatred, it does," Montreal centre Lars Eller said.
"Do we need it to win? The more motivation the better, whatever gets you going."
One might think it would serve as extra motivation for the Rangers, and that's likely true.
As Vigneault put it, "as games progress in the series, the competitive nature of players and coaches come out. Obviously, every game has their moments. Every game has their incidences where sometimes blood can boil."
It got sufficiently heated on Thursday to cost the Rangers' Dan Carcillo a 10-game suspension for abuse of an official – he appeared to elbow and cross-check a linesman after running at Prust from behind.
"Games like that are where rivalries are created," Desharnais said. "In the playoffs you need to find motivation and get your emotions up."
Should Stepan not be able to play for Game 4 of the series on Sunday – and the Rangers weren't willing to provide a timeline until after a surgical procedure expected on Friday – it would be a huge loss.
The Minnesota native is New York's second-leading scorer in the playoffs, and has five points through the first three games of the conference final centring Chris Kreider and Rick Nash, which is perhaps the team's most effective unit.
Montreal could argue – and in fact did – that the Rangers now have a taste of what it's like to lose a key player under rage-inducing circumstances.
"You know what? If there is a team that can understand the loss of a player, it's us. We lost Carey Price in the first game of the series with the hit on Kreider … and we felt frustrated at the time," Montreal coach Michel Therrien said. "You never want to see players, first of all on our side or even on the other side, get hurt. You don't want to see that."
He also, as coaches tend to do in such circumstances, offered a stout defence of his guy.
Framing his response to include Kreider once again, he said Prust "tried to finish his check. His intention, honestly was not to hurt Stepan."
Prust was looking at a suspension in any event for crunching his shoulder into Stepan's chest and head just a couple of minutes into the game – the puck was long gone – the fact his quarry was injured could well lengthen it.
What isn't clear is how badly Stepan's jaw was fractured and how long he'll be out.
He missed only 5:49 of game time (and just over 13 minutes of actual time) before returning to finish the contest – he later assisted on the Rangers' tying goal.
Vigneault said the initial in-game assessment and X-ray were negative, but that Stepan was re-examined on Friday morning and a fracture was discovered.
If the injury prevents Stepan from playing in Game 4, which again will be a pivotal encounter, it will compound the loss of centre Derick Brassard to injury in the series opener.
If he miraculously returns, it could pump some air back into the New York dressing room.
All in all, the sort of circumstance that raises everyone's dander and further stokes a rivalry.