It was the New year's Eve when not seeing was believing.
It was the NFL game played on a smoky, surrealistic soundstage, before an invisible crowd that was suspended like a ghostly chorus beneath a bank of stadium lights.
It was the day when weather changed history - Eagles' history, anyway.
It was the Fog Bowl, 20 years ago today, and it was more than just the Eagles' most fantastic playoff game. It also was a turning point for the franchise.
Everybody remembers how the fog rolled into Soldier Field in Chicago. Everybody remembers when the Eagles and Bears disappeared into the milky mist. Everybody remembers the scene and the score (Bears, 20-12).
But what also was truly significant about Dec. 31, 1988 was the way it changed the Eagles forever. In effect, that team never really emerged from that fog.
And much of what has followed over the last two decades - right down to the identities of the organization's current owner, head coach and quarterback - can be traced, at least indirectly, to the events that started when somebody in the press box said, "Hey, I think there's a fire."
The Eagles of that era are best known for what they didn't do: Win a playoff game.
For all their talent and all their bombast - much of which came from their blustery coach, Buddy Ryan - those Eagles never came close to realizing their potential.
They walked and talked like a championship-caliber team. And they played like one, too, for single games or brief stretches from 1988 through 1990 when they were remarkable for their defensive dominance and offensive explosiveness.
But it never lasted, and it always ended badly: Either at home in the playoffs against Washington and the Los Angeles Rams, or in that meterological maelstrom in Chicago.
Of course, nobody knew that on that Saturday morning when the team's future seemed brighter than the sunny skies over the stadium on the shores of Lake Michigan.
Two weeks earlier, the Eagles beat the Dallas Cowboys 23-7 in Texas Stadium - Tom Landry's last game, by the way - to finish the regular season with a 10-6 record and clinch the NFC East title.
The NFC East in those days contained the last two Super Bowl champions (Washington after the 1987 season, and the New York Giants after the 1986 season). But the team to watch was the one from Philadelphia.
The Eagles were a gathering storm, filled with some of the most talented young players in the sport. Quarterback Randall Cunningham was 25. Defensive end Reggie White was 27. Defensive tackle Jerome Brown was 23.
The defense also featured end Clyde Simmons (24), linebacker Seth Joyner (24), cornerback Eric Allen (23) and safeties Wes Hopkins (27) and Andre Waters (26).
The wide receivers were Mike Quick (29) and Cris Carter (23). The tight end was Keith Jackson (23). The running backs were Keith Byars (25) and Anthony Toney (26).
Ryan knew he had an imposing team that was poised to make big noise. The coach liked to make to make big noise of his own. He also like to spend owner Norman Braman's money.
For three days before the game, the Eagles stayed at The Point, an exclusive resort outside Phoenix, and worked out in the warmth of the Valley of Sun.
The day before the game, the Eagles flew to Chicago. Ryan ordered the team buses to circle Soldier Field on the way to the team hotel and honk the horns because "we're not sneaking into town."
Looking back, it seems kind of silly and sophomoric. But there was a brash and bright-eyed youthfulness to the Eagles in those days, a cocky playfulness and lack of sophistication that seems refreshing compared to the button-downed, corporate culture of today's NFL.
Ultimately, that attitude contributed to that team's downfall. They needed to be a little more uptight, a little more meticulous. They needed to sweat a few more details.
But that loose, brazen approach was part of their charm. Besides, nobody knew on the last day of 1988 that the team on the verge of greatness would never make good on its promise. Nobody knew that injuries and bad timing and bad karma and Ryan's stubborn refusal to strengthen the offensive line would leave that team unfinished and unfulfilled.
The Eagles drove up and down the field that day. Cunningham passed for 407 yards, still a franchise playoff record by 50 yards. Jackson had 142 receiving yards. The team generated 430 yards - the second-highest total in franchise playoff history, topped only by that 58-37 victory over Detroit in 1995 - as well as 22 first downs.
But they couldn't get in the end zone. Cunningham threw an apparent touchdown pass to Quick, but it was nullified by an illegal motion penalty on Toney. Cunningham threw another perfect pass that should have a touchdown, but a wide-open Jackson dropped the football.
The team's only points came on four field goals by Luis Zendejas, who would be kicking for Dallas - and making news as a central character in the controversy that spawned to 1989's "Bounty Bowl" - by the following November.
And then the fog rolled in.
It happened just before halftime, and it was the weirdest thing. Soldier Field had this wide concourse beyond the corner of the north end zone, and there was a little half-wall on the outside.
The fog rolled in like liquid - it just poured over that little wall. At first, it looked like smoke from a fire. Soon, the whole stadium was blanketed in mist.
What happened next probably would never happen today: NFL officials gathered many of the media people in the press box and escorted them down to the field. We watched the second half from the sideline.
And that was an incredible scene. Players would disappear and re-appear, depending on the thickness of the fog. You couldn't see the crowd. You could just hear the fans, the sound emanating from smoke-covered seating sections that were haloed by those stadium lights.
Eagles wide receiver Gregg Garrity was talking meteorology in the locker room after the game.
Everybody was excited. Everybody knew they had been part of something special. And everybody figured it was just the start of a long and successful playoff run for the Eagles.
Everybody was wrong.
There were some memorable moments over the next few seasons. The Eagles went 11-5 in 1989 and 10-6 in 1990. Cunningham unleashed a 91-yard punt on a windy night in Giants Stadium. He also rushed for 942 yards in a season. The Eagles sacked Troy Aikman 11 times in one game. There was the Bounty Bowl and the Pork Chop Bowl and the body-bag game.
But so much seemed possible on the morning of Dec. 31, 1988. Not much of it happened.
The Eagles lost in home playoff games to the Rams after the 1989 season and to the Redskins after the 1990 season. Ryan was fired after the 1990 season. Cunningham got hurt in the 1991 opener. The 1992 team finally won a playoff game but was pummeled the next weekend by a young Dallas club on its way to three Super Bowl titles in four seasons.
Jerome Brown died in a car accident in June, 1992. Keith Jackson became the NFL's first true free agent. Reggie White signed with Green Bay.
Just like that, it all faded away. The Eagles went from this young, supremely talented team on the brink of something special to a shadow of their recent past.
Suddenly, they were a team with Rich Kotite as their coach and Antone Davis and Leonard Renfro as their high draft picks.
It's wild speculation, kind of like postulating that a butterfly flapping its wings in China can cause a hurricane in Florida.
But what if the fog never rolled in?
Or what if the Eagles emerged from the mist with a victory?
The tag that doomed Ryan and defined Cunningham - can't win a playoff game - would never have been applied to either man.
So maybe Ryan wouldn't have been fired after the 1990 season. And maybe his continued presence - plus, some additional playoff success that might have sprung from the confidence that resulted from a victory in 1988 - would have moved Braman to make a different decision with regard to selling the team.
Maybe Braman would have sold in 1992 instead of 1994. Or 1996. And maybe that would have meant that Jeffrey Lurie wouldn't have been in position to purchase the team.
No Lurie. No Ray Rhodes, perhaps. No Andy Reid, then, and no Donovan McNabb - not in Philadelphia, anyway.
Hey, those butterfly wings can create some havoc in chaos theory.
Maybe this, maybe that.
What is true is that 20 years ago today the fog rolled in and the Eagles disappeared into the mist.
Looking back, it also seems clear they never really came out.