[[caption-width-right:350:[[ImplacableMan He just won't die...]] ]]
* Don. Creator/RobertCarlyle is good at creepy anyway, but him as an Infected was nightmarish, and that's not an easy thing to do. The scenes where he's first turned and what he does to Alice are horrifying, and the fact that he seems to [[ItCanThink retain]] some very basic reasoning just makes it worse. He's not a mindless, murderous creature like the Infected in [[Film/TwentyEightDaysLater the first]] movie--he's still very murderous, but he's got enough marbles left to actively hunt his children through London.
* The Infected, as they seem to have some sort of basic intelligence. Not enough to avoid things like snipers, but enough to ambush you, or [[EyeScream kill you in even more exciting ways.]]
* When residents in the center are put into a sort of 'quarantine room' at the first sign of the infection. It's a small room, and there are a lot of people. Making it very cramped and claustrophobic. Bad enough by itself... But then a single infected gets inside through the only entrance, and everyone in there realizes they have no way to escape.
* Andy's nightmare near the beginning, in which his mother peels off her own face while staring straight at the camera.
* [[https://www.youtube.com/watch?v=Xh2kwqss0dQ The attack on the cottage in the beginning]]. The scenes really make you feel as if you're right there in the middle of infected territory, so when the attack starts the panic feels real.
** That shot where Don's running away and a horde of infected come running over the hill is downright terrifying.
* [[spoiler: Alice's death]] is just so ''damn'' brutal...
** [[spoiler: For those who do ''not'' wish to see the infamous scene involving Alice's death ([[TheresNoKillLikeOverkill One cannot blame you...]]), here's a summary: After Don kisses Alice, he begins to react and thrash horribly in [[CallBack the first 10-20 seconds of being infected]] finally becoming a Rage-inducted infected. After hearing Alice scream at him in horror, he then proceeds to ''beat her repeatedly'', making her spit out blood, and then ''rip a piece of her neck off''. And then when getting a flashback of Alice's wide-eye horror from the above mentioned cottage scene, he then proceeds to '''[[EyeScream shove his thumbs into her eye sockets, reducing them into a bloody mush]]''', all while she's screaming in pain and horror. And after killing her with ''that'' action, he proceeds to ''smack her head around as if trying to see if she really is dead'']]. Dear god in heaven.
** A commenter in the clip of [[spoiler: Alice's death]] pointed out something terrifying: [[spoiler: Since Don [[ItCanThink retained some intelligence]], it's a ''possibility'' he was attempting to resist the infection when he turned into a Rage-Infected after kissing Alice due to [[ItsAllMyFault his guilt of abandoning his wife]]. However upon hearing Alice scream out his name in horror after he turned, ''[[NeverMyFault his mind began to blame his wife instead]]'', hence why he brutally kills her. There's also the fact commentators pointed out Don sports a SlasherSmile after killing Alice]].