"All whales in captivity are psychologically traumatised." 

That's the trailer for Blackfish, a documentary about killer whales that do just that. If you're someone like me, who grew up loving Free Willy, it's powerful stuff. And that's just the two-minute preview.

If the final piece is anywhere near as intimidating and powerful as this simple, effective poster, which looms over you in a cinema foyer like it's about to gobble your face whole, Blackfish is set to one of the best (and most upsetting) films of the year. 

Blackfish is out in UK cinemas on Friday 26th July. Read on for the trailer.