On arrival she secures passage up the river with steamboat skipper Frank (Dwayne Johnson) but they have German Imperial aristocrat Prince Joachim (Jesse Plemmons) hot on their heels who wants the Tree's secrets for himself.
With the moribund Pirates of the Caribbean franchise beyond redemption at this point, Disney have tried a similar formula here and mostly it works well.
It's kind of "The Mummy" (right down to foppish brother) with a bit of Indiana Jones and PotC thrown in. It's about as formulaic a star vehicle as the poster suggests but that doesn't matter because Johnson and Blunt are absolute masters of delivering this stuff well. Has Emily Blunt ever put a foot wrong?
The PotC influence is most obvious in a set of heavily CGI blobby transforming cursed undead Conquistadors that add little (we had Prince Joachim for a villain already) and probably cause it to be about 20 minutes too long.
It's twee, safe as fuck and goes nowhere interesting at all but I had beer and pizza while watching it and laughed along with it not at it. Solid family entertainment 7/10 because it does everything it said it would and even had a tiny twist that worked well.