Book #1 in the "Resident Evil" series. Takes place at the same time as "Zero Hour", book #0. Where "The Umbrella Conspiracy" is told from the POV of the Alpha Team, "Zero Hour" is told from the POV of the Beta Team that crashes its helicopter right at the beginning. I read ZH first - unfortunately. Why? Even though the events should take place simultaneously, there are so many errors, it's not even funny. Rebecca is the main heroine of ZH, the young field medic slash chemist and she kicks major butt, zombies, other monsters, whatever, she survives the self-destruction of the training facility and THEN goes to the Spencer estate - in TUC, she doesn't have a gun, she doesn't recognize the monsters, she ran towards the Spencer estate together with her team right away, so basically, ZH didn't happen. In ZH, Wesker is at the training facility - in TUC, he's the leader of the Alpha Team. And that totally ruined the fun. So, my advice, either read "Zero Hour" or "The Umbrella Conspiracy", NOT both!
Another thing - the beginning was awesome and I was totally hooked, the team was simply great. But soon, it was back to the same old, same old: open a room, find a clue, solve a puzzle, find a key, fight a monster, move on - lather, rinse, repeat ad infinitum. Seriously, dear author, you really do NOT have to copy everything you see happening on your computer screen, scene for scene. It was rather ridiculous after a while. And what's with the "let's split up" routine? What a great idea to split up in a house that's built like a booby-trapped maze.
I think that this will be the last book in the "Resident Evil" series that I'll read. You read one book, you read them all. It's a carbon copy of a rehash of a carbon copy.