(CNN)Kenneth Branagh continues to explore Hercule Poirot, the man, and not just the master sleuth in "Death on the Nile," a star-studded sequel that powers past its casting baggage to both build and improve upon its predecessor. The narrative arc that began in "Murder on the Orient Express" thus brings the story to what feels like (or should be) a natural conclusion.
Reprising his role as producer, director and star and again working with writer Michael Green, Branagh opens the film with a flashback to World War I, adding layers to the origins of Poirot's melancholy. But soon enough, Agatha Christie's creation is however grudgingly back on the case, joining his young friend Bouc (Tom Bateman) on a trip down the Nile along with a honeymoon party where, as luck would have it, everyone seems to have a motive to murder the bride.
"I am hiding from cases," Poirot protests. But where's the fun in that, and besides, who can say no to a wealthy and glamorous heiress asking for help?
That would be Linnet Ridgeway (Gal Gadot), who is celebrating her whirlwind romance and marriage to Simon Doyle (Armie Hammer), who she met when he was engaged to her longtime friend Jacqueline (Emma Mackey, more than holding her own with the bigger names here).
Heartbroken, Jacqueline has pursued the couple on their excursion to Egypt, culminating on a boat populated by the small wedding group. The course of events leaves Poirot playing catchup much of the time, before eventually putting the pieces together in a way that's every bit as satisfying as "Orient Express."
Hammer has become a problematic figure due to sexual-assault allegations he has denied, but unlike some other productions that moved to replace him, this one (actually shot some time ago) has essentially allowed him to blend into the ensemble.
The characters have also been nicely upgraded, in some subtle but significant ways, versus the 1978 version, which cast Mia Farrow, Simon MacCorkindale and Lois Chiles as the central triangle, and Peter Ustinov as Poirot.
While Gadot and Hammer represent two of the most prominent names, the performances are topnotch across the board, perhaps foremost among them Sophie Okonedo as a blues singer, whose daughter (Letitia Wright) is one of Linnet's old friends.
There's obviously a bit of calculation in introducing more depth to Poirot, making him more interesting for Branagh to play. Yet the filmmakers manage to incorporate that without detracting from the central mystery, and the pace chugs along briskly enough, with plenty of stunning scenery when outside those stuffy cruise rooms.
Already riding high on this week's seven Oscar nominations for "Belfast," Branagh has delivered a polished follow-up to his earlier Christie excursion that won't win any awards, but which seems to bring this conjoined chapter to a satisfying close.
While that might not translate into as bountiful harvest from theaters, this sort of amiable mystery should enjoy a long shelf life. If so, Branagh and his alter ego could be tempted not to "hide from cases" for very long.
"Death on the Nile" premieres in US theaters on Feb. 11. It's rated PG-13.