This was Trelawney's idea, unsurprisingly. Much to Javier's dismay, he was forced into a guard uniform and told to play a guard role. As a Mexican in 1899, he didn't have much choice than to play the guard role, though.

So, here he was, standing beside a door in a guard uniform and a rifle in his hand. Stuck staring at the rich white men wasting away their money. Keeping a careful eye on his friends to make sure they didn't fuck anything up.