The official novelization of the #1 smash hit film Happy Death Day and its sequel Happy Death Day 2U, from Blumhouse (Split, Get Out, The Purge franchise) and Universal Pictures.

In Happy Death Day, Teresa "Tree" Gelbman's birthday is the worst day of her life, starting when she wakes up in a stranger's bed. It's also the last day of her life, ending when she's killed by a psychotic killer with a knife. She's dead. And then she wakes up in a stranger's bed, it's September 18, and she has to live it all over again…until she's hunted down and wakes up, again, and again. It's a Groundhog Day situation, only with murder, guns, and mean girls, and Tree's only shot at living to see the next day is to relive the day of her murder, over and over, until she discovers her killer's identity.

Happy Death Day 2U picks up the story without missing a beat. Tree Gelbman thought she'd finally lived to see a brand-new day. But when she wakes up on her same birthday and an all-new psychopath in a mask is out to kill her and her friends, she's going to find out that all the rules have changed. Death makes a killer comeback.