A win Sunday in Anaheim, Calif., to extend their NHL playoff series with the Ducks and avoid elimination would be that.
Calgary's long history of futility in the Honda Center aside, these Flames are 0-4 and have been outscored 18-6 there this season.
"My message is 'shock the hockey world,'" Hartley said Saturday in Calgary prior to the team's departure for California. "Obviously we're at the edge of the cliff right now.
"We want to keep going. This has been a great season for us."
Down three games to one in their best-of-seven Western Conference semifinal, the Flames draw their confidence from a season of improbable comebacks and an endurance race to the wire just to get into the playoffs.
A team in the second year of a rebuild made fools of oddsmakers and predictors this season. The Flames feel there's another rabbit or two to pull out of their hats.
"With a team like this, anything is possible I feel like," forward Johnny Gaudreau said. "We've been down in games before. I feel like this is the perfect scenario for us."
Game 6, if necessary, is back in Calgary on Tuesday. A Game 7 would be Thursday in Anaheim.
"We know if we can get in there and get a win tomorrow, then we're coming back here," Calgary defenceman Dennis Wideman said. "If we can get a win there, it will be a different series."
A victory in Anaheim would shake a monkey inherited from previous teams off the Flames' backs. Calgary hasn't won a regular-season game there since 2004. They won a lone playoff game in Anaheim in 2006.
"That building has been a struggle for us, but we know we can go down there and get a win," forward Mason Raymond said. "That's the biggest thing, is the belief we can do that."
The Ducks downed the Flames 6-1 and 3-0 at home to take a 2-0 lead in this series. Trailing 3-2 deep into the third period of Game 3, Gaudreau tied it and Mikael Backlund scored the overtime winner at the Scotiabank Saddledome.
The Flames played their best game of the series even-strength in Friday's Game 4, but special teams were their downfall. Anaheim scored a pair of power-play goals and killed off a Calgary two-man advantage in the third to win 4-2.
A Gaudreau turnover that led to an Andrew Cogliano goal, a Joe Colborne double minor for high sticking that opened the door for Matt Beleskey's game-winner, and failure to convert that 5-on-3 were the differences in the game.
"It's the smallest things right now," Wideman said. "Probably five-on-five, it was our best game of the series. Funny how it works sometimes, you play your best game and don't get the result that you want.
"I think if we keep playing that way five-on-five, keep playing that forecheck game and keep coming at them, I think we'll have a chance to win."
The Flames were able to pen the Ducks in their defensive zone to lead 2-1 after the first period. Rugged wingers Lance Bouma and Michael Ferland returning to the lineup from injury increased Calgary's forecheck pressure and opened up room on the ice for the Flames.
Calgary's top line produced its first even-strength goal when Sean Monahan scored in the first period. The Flames blocked 23 shots to Anaheim's 14.
Fowards Gaudreau, Monahan, Backlund, Ferland, Bouma, Sam Bennett and top defenceman T.J. Brodie are on learning curves in the first NHL post-seasons of their careers.
But there is "zero" margin for error Sunday against the heavier, more experienced Ducks, Hartley said.
"Last night, they made us pay on basically every mistake that we made," the coach said. "We didn't make many mistakes, but they made us pay and that's what good teams do. You can tell that they've been there.
"They're talented and experienced. They know where to push and they know where to slow down. That's what we're learning right now. It's all about a learning process for us, but we want to keep winning at the same time."