LOS ANGELES, July 9 -- Two years ago, after a blistering and unprecedented streak of billion-dollar-grossing movies, the Marvel superhero films took what was meant to be a short hiatus.

When that big-screen break - involuntarily extended by the Covid-19 pandemic - finally ends Friday with the release of Black Widow, Hollywood will be watching closely to see if Marvel still has its mojo.

"I would say it is in flux, at a pretty crucial turning point," said Kendall Phillips, a Syracuse University professor who specialises in pop culture.

"The key question is - can Marvel do it again?"

Black Widow - which finally gives Scarlett Johansson's Russian assassin-turned-superhero Natasha Romanoff her own spin-off - has been sitting "in the can" ...