EXPOSITION The title is The Avengers during present time where Loki plans to attack New York and invade the world and comes from a portal made by the Tesseract in a S.H.I.E.L.D. base and invades the base by mind controlling people there and leaves on a stolen jet.
CONFLICT That Loki will invade New York and the world with his mind controlled people and the Chitauri army.
RISING ACTION When S.H.I.E.L.D. gathers superheros to apprehend Loki and the Tesseract while Loki opens a portal to let the Chitauri invade earth and The Avengers fight them and manage to get Loki's staff which they'll use to close the portal and meanwhile someone at S.H.I.E.L.D. launches a nuke to destroy New York and the Chitauri army with it, but Iron Man catches it.
How do you know they will be back?
They will come when they are needed to
CLIMAX When Iron Man throws the nuke into the portal and destroys the Chitauri main ship and disables the army right before Black Widow closes the portal with the staff
FALLING ACTION When Loki is apprehended and the Tesseract is taken to Asgard for safekeeping
RESOLUTION It ends with Nick Fury stating the Avengers will be back when they are needed