Right then, having seen the aforesaid Marvel movie, let's sum it up as follows...
It all begins in Lagos, where there's a big fight between Captain America and some others. This hurts people. So the United Nations say the Avengers shouldn't hurt people. But Captain America's friends fall out with each other, and then there's another big fight in Vienna when his old wartime friend Bucky appears. Then Captain America and Iron Man pick teams, and then there's another big fight in Berlin that goes on for a very long time around an amazingly deserted airport. (Have you been to Berlin Templehof? Deserted, it never is.). After that, Captain America (with Iron Man and others) go to somewhere vaguely Russian and then there's another big fight. (Do try to keep up.)
I might have missed out mentioning some of the fight scenes, but that's about it. There's a lot of punching, some smart dialogue, a bit of meaningful stuff about Friendship and Regret and Guilt, and Robert Downey Jr chews up the scenery a lot. I do hope that Robert Downey Sr is suitably proud, wherever he is.
And at the very end, with quite a few other people (many of whom were bald men) I sat through 10 minutes of credits to see a one-minute ad for the next Spiderman film. Not that there's anything wrong with being bald, no sirree. But we all did it, meanwhile gazing at credits and wondering for the umpteenth time what a Key Grip or Chief Wrangler might be. There were enough people involved in making this film to staff a small country ending in '-avia.' (You know... the one that got trashed in the previous movie.)
To be honest, I'm not sure that knowing the plot would spoil anyone's enjoyment of a film like this, and I'm a sucker for them. But there's a point when lots of people on screen are hitting each other over the heads with cars, trucks and airliners and you Just Don't Care. And there's going to be another X-Men movie soon which will involve lots of superheroes ganging up to hit Something Else over the head with mountains or pyramids or suchlike.
I finally left the cinema feeling vaguely hungry for something that didn't involve hitting people over the head with airliners or pyramids. How odd, and how new.