As the film opens, the ruler of Wakanda has died from a sudden illness and those close to him – his fellow actors – are grieving. Life and art cross paths as King T’Challa is farewelled in a forest by mourners in white before departing skyward in a gleaming black coffin embossed with T’Challa’s crossed forearms. The tears are real.

Grieving most are his mother, now Queen Ramonda (Angela Bassett at her most melodramatic), and sister Shuri (Letitia Wright), a science nerd with a little sister vibe who tried to save her brother but failed.

T’Challa’s great ethical challenge had been whether to seal Wakanda – a prosperous, exotic Black Nation rich in colour and technology – from the rest of the world. Clearly, the world had other ideas. Summoned before the United Nations, Queen Ramonda responds by dragging into the chamber the bedraggled (French) mercenaries she captured trying to steal Wakanda’s precious metal, vibranium.

The arenas of action in what is a long and sometimes disjointed story are Wakander, which is under attack, and the newcomer world of Talokan, a moody underwater kingdom based on Atlantis and an addition to the Marvel universe. Its mysterious king is Namor (Tenoch Huerta), who flits about with buzzing ankle wings and heads an army of warriors, one in a gorgeous shrimp head dress. They commandeer whales for rides and breathe underwater and on land.

There is a lot of globe-trotting and time travel as we dart between Haiti, CIA headquarters in Langley, a Boston university and the Yucatan Peninsula in the 16^th century. It all makes sense at the time. The introduction of a young female, black engineering whiz who knocked up a vibranium detector for the CIA after she was recruited by agent Everett Ross (Martin Freeman) is a nice touch, although the poor girl is borrowed by Wakanda then kidnapped by Talokan.

The Haiti strand becomes central as former agent Nakia (Lupita Nyong’o) returns to Wakanda, where she self-exiled after T’Challa’s death. She joins a mashup spectacle of power and ferocity delivered with style by the warrior force, the Dora Milaje, including Okoye (Danai Gurira) and Aneka (Michaela Coel in a minor but slick role).

There are moments that recall the tribal grandeur of the first Wakander, but not enough for my liking. Cartoonish aerial and underwater battles rage, although Shuri, now in Black Panther mode, settles a battle for ascendancy with an arm wrestle.

There may be neck rings and lip plates but some of Wakander’s identity has been sacrificed in the interests of an expanded Marvel playbook.

By the end, Shuri must decide what kind of leader she wants to be and so, it seems, does Namor. We get the feeling they will meet again. The final credits skirt back to the grieving but be sure to stay, and not just for Rihanna’s song.

Black Panther: Wakanda Forever is in cinemas now.