Ten years on this f—ing beach. Let’s go home.

Now a decade into his time at the top of the San Francisco 49ers, Kyle Shanahan’s quest for his first Super Bowl title began to feel a bit like his own personal Odyssey this summer.

His own men (Brandon Aiyuk) turned on him.

He had to navigate a swirling whirlpool (his Tesla’s autopilot feature).

The temptation of the sirens’ songs (of East Palestine, Ohio) proved to be too powerful.

Now, here he finds himself on an unknown island in a faraway land, just hoping it is one stop on the way to the one thing he wants most of all but cannot have — not yet, anyway.

The 49ers open the season under the brightest lights imaginable, against the Super Bowl favorites and division rivals, in front of almost 100,000 in the NFL’s first game in Australia. But at the same time, squint and you can see the lights beginning to dim on their current era.

Shanahan’s hair has grayed and his face has wrinkled since they made their first trip to the Super Bowl seven years ago. It’s been three years since their last appearance.

Even the team that thwarted them twice, Patrick Mahomes and the Chiefs, have begun to look mortal. Some part of him must be wondering if they’ll ever make it back and get another crack.

They’ve got two monsters to contend with in their own division who only seem to be getting stronger. Meanwhile, the same core group of 49ers gets another year older.

More than ever, it looks like it’s now or never for the players that will be remembered as the faces of this era of 49ers football, whether it’s Shanahan’s sole one or merely his first.

The 49ers would never move on from Shanahan, who’s brought the most stability and success the organization has seen since the heydays of the Joe Montana-Steve Young dynasties.

But would it be all that surprising if after a decade of coming up short in San Francisco, Shanahan decided he wanted a bite at the apple somewhere else?

When they take the field Thursday night, there will be six Niners remaining from the original Super Bowl squad and just one — Renardo Green — who they have added since in the first or second rounds of the draft. They hit big on one notable late-round pick in quarterback Brock Purdy, but the Niners are now paying him $53 million a year — almost 20% of their cap space.

George Kittle is 32 years old and attempting to come back nine months after tearing his Achilles tendon. Christian McCaffrey turned 30 over the summer and is coming off the largest workload of his career. Nick Bosa will turn 29 in October, not long after the one-year anniversary of his third knee surgery. Trent Williams is 38, Kyle Juszczyk 35, Deebo Samuel 30, Fred Warner 29 and so on.

At least we know they’ll all be on hand and in uniform in Australia. That much can’t be said for Jed York, who skipped out on his first scheduled engagement since his prostitution arrest last month, sending CEO Al Guido to represent the team at the NFL owners meetings.

Shanahan revealed that York spent much of the summer at his family’s home in Ohio, near the trailer park where he was arrested, after filing for divorce in May. That alone was a major departure for the owner who had been raising his two children in nearby Los Altos Hills and was a frequent presence at the facility he helped lead the effort to build.

Could York’s step back from the spotlight portend something more? There’s been more recent tumult upstairs, with Paraag Marathe, one of the Yorks’ top deputies, departing to run the two English and Scottish soccer clubs the family controls under the 49ers Enterprises umbrella.

Their division-rival Seahawks just sold for $9.6 billion in a smaller market. Is there a figure the 49ers could fetch that would convince York to listen if his influence is already diminished?

Does a sale set off a chain of events that leads to Shanahan’s departure? They have more than a strong working relationship together with general manager John Lynch.

For now, it’s only a hypothetical. But it shows how fragile the 49ers’ foundation suddenly is.

That only ups the ante on this season. But it also makes it that much more special.

Sure, the Rams might be unbeatable, the Seahawks just about were last season, but McCaffrey is healthy, Bosa is healthy, Kittle is healthy, Warner is healthy and Purdy is Purdy. So the 49ers have a chance, which is more than most teams can say.

Whether it’s enough to finally get Shanahan to the promised land is something that only the adventure of a 17-game schedule and a month of postseason play can determine.

The journey begins Thursday night in Australia.