It was a teaser that basically told you nothing except "BWAMP" and Leo standing on a roof.
The new teaser for Dunkirk, his follow-up to the slightly more divisive Interstellar (it was one of my favorite films of the year), has arrived in equally confounding fashion. Even the synopsis tells you nothing:
“Dunkirk” opens as hundreds of thousands of British and Allied troops are surrounded by enemy forces. Trapped on the beach with their backs to the sea they face an impossible situation as the enemy closes in.”