The first Borderlands DLC I've played. Zombie island, or it's full title. The Zombie Island of Dr. Ned (Insert evil laugh here). The main plot of this DLC is to go to Jacob's Cove, a small town in a rocky... well, cove. And as the name of this add-on implies, zombies have infested Jacob's Cove and all the surrounding areas. You first start the DLC by being literally teleported to a harbor, after a small cutscene has played explaining the situation, with standard humor that Borderlands is filled with.
Like zombie games before this one, there are multiple types of zombie. There's the standard run of the mill zombie. There's a zombie that spits, and by Christ they're accurate sods. Psycho zombies, which are just zombified psychos (like you couldn't tell). Soldier zombies, which are by far the scariest because of missing limbs. And large zombies which really like to throw things at you... Like explosive barrels.
The first mission is to actually get to Jacob's Cove, and to do that you're going to have to plough your way through a few waves of zombies. to be honest they're not that terrifying, they occasionally make you jump if you're playing at night, but that's about it. When you've reached Jacob's Cove, surprise surprise, there's zombies there as well! So it's up to you to turn on the town's defensive guns, why the town's people didn't do this in the first place baffles me. After that, it's your job to find Dr. Ned and put an end to the zombie outbreak.
To be honest, zombie island has got quite a bit of challenge to it, zombies will swarm around you instead of the typical, single file and get shot method of so many other games, plus they level up with you, constantly making the little (And not so little) blighters take big dents in your ammunition reserves... And face.