It's probably just a fact of postseason life for Capitals fans at this point that any time the team loses a game, or falls behind in a game, that the fear kicks in. And so Zach Hyman's first-round Game 4 goal to cut Washington's early 2-0 over the Maple Leafs lead to 2-1 was an uh-oh moment on Wednesday in Toronto. So was the Brooks Orpik slashing penalty late in the second period that meant the Leafs would start the third with a long two-man advantage. So was the Auston Matthews goal that cut the Caps' lead to 4-3 with eight minutes left. So, even, was Jake Gardiner's shot attempt from the point in the final seconds with Washington clinging to a 5-4 lead.

Washington's been through so much disappointment over the past decade that fans could be forgiven for preparing themselves for the worst, no matter how good the team looks on paper, or how many regular-season games it won, or how sky-high the expectations are. In Game 4, the worst never came: Washington held on for the win to even the series at two, and for the first time in this series, the game didn't even require overtime. But as the action shifts back to Washington for Game 5, the juxtaposition of the Stanley Cup-or-bust Caps and the happy-to-be-here Leafs has given us the most compelling series of the first round.

The Maple Leafs have unusually little to lose for a playoff team, while the Capitals have absolutely everything to lose. The difference in expectations in this series is almost comical: The Leafs' season is already a successful one, no matter what happens next. Just getting this far is a big step forward for the franchise, and it's apparent that a strong core is in place. But a Washington loss in the first round -- heck, a Washington loss in either of the first two rounds -- would be catastrophic.

This isn't a typical underdog situation, because it isn't a typical 1-8 matchup (or 1-4, or 1-WC 2, or whatever we're calling it in the NHL's current, broken playoff format). Expectations for the Leafs are low, even for a conference's lowest-seeded playoff team. They're a season removed from the worst record in the league, and their rebuild wasn't expected to result in a playoff spot this soon. It's not quite right to say they're in the early stages of reforming the franchise: It's been three years since Brendan Shanahan took over as president, and two since Mike Babcock and Lou Lamoriello arrived. But the overhauled roster didn't get its centerpiece until Auston Matthews was drafted last June. Toronto being Toronto, it'll soon be expected to win and win big, but the Leafs had been a mess for so long that evidence of mere competence is real progress.

And then there's Washington, a franchise whose fan base gave us this graphic just three games into the playoffs:

(Yes, that first figure dropped as the night went on. And no, that doesn't make the above image any less perfect.)

The Capitals, infamously, have yet to advance past the second round during the Alex Ovechkin era, despite six division titles and two Presidents' Trophies through 2016. This year brought another of each, and a deadline trade for Kevin Shattenkirk, the latest final piece of the puzzle, only raised expectations further. This is a team that's desperate to win, and it's a fan base that is, perhaps, even more desperate to win.

"Pressure is a wonderful thing when you're the underdog," said Toronto coach Mike Babcock last week. He could have added that it's even more wonderful when the favorite has as much baggage as the Caps do.

Daniel Winnik, the Caps forward who's previously played for Babcock, accused his former coach of trying temper expectations. Washington coach Barry Trotz, meanwhile, acknowledged the Caps' recent history, but argued that this team is different. Via the Toronto Star:

"We had pressure the last couple years, and that's been common here. I think we're way better with it. I listened to Babs' comments, he's playing you guys with that, but I think we can understand that.

"We expect ourselves to do well, that's the expectation that we put on ourselves. I don't think that's going to change. I think we're way more prepared for that, maybe than we were last year."

Babcock is correct here: All the pressure is on Washington. On Wednesday night, it handled that pressure well, even as the Air Canada Centre buzzed in the third period when the Leafs drew to within a goal. But the dynamic of this series is such that, even though it's tied and moving back to D.C. for Game 5, the pressure doesn't shift away from the Caps. The Leafs are happy to be playing in this series at all; the Capitals will only be happy if they can get out alive.