The slick salesman that’s Mr. Dickens is an oily character who’s very… entrepreneurial in his ways. When you first encounter him, you’ll need to fend off the enemies before driving his carriage back to the town of Armadillo.
But of course, it’s no easy ride, so make sure you have your best rifle at the ready for the journey. Staying on the main road is pretty much essential as Dickens’ life will drop quicker if you try and go off-road or hit any obstacles on the way (or - obviously - if he’s shot).
When you get ambushed by bandits, you can either wait for a straight stretch of road before turning to lock onto them and shoot them, or you can use Dead Eye to slow things down a bit and take them out that way. Keep this up until you reach Armadillo where you can drop Dickens off at the doctors to get patched up.