Cast: Josh Brolin (voice of Thanos), Robert Downey Jr., Chris Hemsworth, Mark Ruffalo, Chris Evans, Scarlett Johansson, Benedict Cumberbatch, Tom Holland, Chadwick Boseman, Zoe Saldana, Chris Pratt, Vin Diesel (voice of Groot) Directors: Anthony Russo and Joe Russo Rating: 2.5 Stars (out of 5) It isn't hard to see what Iron Man is thinking. At any given point, Robert Downey Jr lets us inside his character's head to show us how Tony Stark thinks, and this - the visible personality, the unmistakability brought by each actor to each character - might be the greatest superpower of the Marvel movies. Most of their actors are now excellent at this, but Downey set the tone back in 2008 with the first Iron Man, and he remains arguably the best at comic-book acting, emoting minus a thought bubble. His eyebrows are his exposition. Therefore, in Avengers: Infinity War , when this vain overachiever talks about giving up dairy yet succumbing to ice cream after Ben &...