As rare as they are, the moment a true sporting dynasty springs up, predictions of it's imminent demise are never far behind.
During the past three seasons, as they've become arguably the greatest team rugby league has ever known, Penrith are no exception.
In perhaps the most enduring proof of their excellence, they have proven every one of those calls to be wildly incorrect.
Since their first premiership win as a group in 2021 they have survived the loss of Stephen Crichton, Kurt Capewell, Matt Burton, Spencer Leniu and Api Koroisau — and all the while kept on winning and winning and winning through their special brand of rugby league brutalism.
They have survived everything and defied decades of measures specifically designed to stop a run like this from happening. There has been nothing they could not overcome and they very well could add a fourth-straight premiership later this year.
But in releasing James Fisher-Harris to the Warriors, the Panthers aren't just farewelling one of the best forwards in the club's history, they're losing a piece of their soul and one of the bedrocks that's made all this possible. This is a loss perhaps not even they can sustain.
It's not a matter of simply taking the money they would have used on Fisher-Harris and ponying up for another prop, although that will almost certainly happen.
Nor is it as simple as replacing his virtues on the field, which shapes as a difficult task on it's own.
Payne Haas runs for more metres, Addin Fonua-Blake is more blockbusting but Fisher-Harris is the most well-rounded props in the league – he's strong in yardage, passes and offloads with intelligence, and holds the middle of the field together defensively.
Plus, he does it all every time he takes the field with a consistency you'd expect more from a machine than a man.
Not many can do what he does every weekend, but his impact runs deeper than that.
Success has many fathers, but ask around at the Panthers and they'll all tell you the same thing. That furious quality they play with, the willingness to always pay the price for success and the endless hunger to fight and dominate and win – a lot of the Panthers carry it in them, but so much of it flows from Fisher-Harris.
It comes from his attitude on the field and off it, the way he trains day-to-day, the toughness he exudes so effortlessly and demands of his teammates so simply and directly that emulating it is not a choice, but a calling.
At their best, Penrith play with the ravenous hunger of starving dogs and Fisher-Harris is the unquestioned leader of the pack.
Nathan Cleary and Isaah Yeo are probably the two best players of the Panthers dynasty. Cleary shared most of the biggest moments with Crichton. Koroisau was transformative, both in the skill he brought himself and the space he could provide for others. Jarome Luai is their energy and Dylan Edwards and Brian To'o are their consistency.
But their most enduring qualities, the things that took them from champions to legends, are best represented in Fisher-Harris.
The resolve, the strength, the consistency, the unbreakable will and the utter lack of mercy for opponents, the willingness to talk – even if Fisher-Harris isn't always one for talking, when he does it makes an impact, like when he declared Parramatta were Penrith's sons – because it's not bragging if you back it up.
And while Cleary and Yeo are the co-captains, so much of what Fisher-Harris does well has been transferred into the club's other players. He doesn't always need to be a captain because he has become a leader by nature, the kind of guy others follow just because it makes sense to do so.
You can see pieces of him in players like Moses Leota, his partner-in-crime who discovered a similar relentless energy, and in Scott Sorensen, who thrived so much in the environment Fisher-Harris helped create he went from NRL journeyman to one of the most decorated roughnecks in the game's history.
There is a clear pattern to Penrith's retention strategy in recent years. To avoid the salary cap molasses that has claimed so many budding dynasties of the past, they had to identify the things in their side they could no do without, the basic elements of their success, and make sure they kept them.
You can lose Crichton, Kikau, Koroisau, Burton and all the rest and so long as you have a defence that's close to unbreakable, enough athletes to dominate the yardage game, Nathan Cleary's kicking game and a belief you can beat down a mountain.
This year could be much better than alright. Penrith are premiership favourites – again – and the prospect of sending their departing players out as winners has been a propulsive force for them many times before.
But Fisher-Harris might be one of the very few departing heroes they cannot replace. There is no way to recreate him in the aggregate through players like Lindsay Smith, Liam Henry and whatever free agent props Penrith will throw their money at.
If there is someone with Fisher-Harris's qualities on and off the field lurking in their endless junior nursery, it won't come out overnight.
You might be born with it, but you still have to learn it. Fisher-Harris himself was in first grade for four years before he turned into what he's become. It's the kind of thing that cannot be found, only uncovered, and is almost impossible to buy, because it must be earned.
Penrith won't fall apart. They've had too much practice at being great for that to happen. Come next season they'll still be among the title favourites along with the Broncos, who are so unlike the Panthers in style but so like them in manner, and likely the Warriors themselves, who must feel like they're tantalisingly close to something special.
But, many years from now, when the history of Penrith's dynasty is written, this might well be the day that's pinpointed as the beginning of the end. There are some losses a team cannot survive, even if it doesn't kill them.