It's quite thrilling from start to end and leaves the audience thinking the whole way through what will happen next. It's not guaranteed 100% predictable.
The following is about two professional hitmen AKA 'assassins', who are paid an exceedingly large amount of money to annihilate specific targets.
The fun comes when they're both assigned to cap off one another, as instructed from their contractors. Their contractors aren't too be seen nor have the assassins met them personally.
The performances of Sylvester Stallone, Antonio Banderas and Julianne Moore are superb. Stallone has finally landed another role to much his stubborn and lethal portrayal of the war veteran 'John Rambo' and 'Jimmy Bobo' (the part he played in 'Bullet to the Head'). Banderas also delivered a fine performance as the anti-hero of the story. It's an amazing twist what the two lead characters: Robert Rath (Stallone) and Miguel Bain (Banderas) have in common, and you're completely unaware of which one is more lethal and with the best advantage of killing the other. It's totally thrilling.
It's definitely one of Stallone's finest roles to compete with Rambo, Bobo and even Marion 'Cobra' Cobretti ( from 'Cobra'), so it's hugely recommendable and fine addition to Stallone's list of films.