BIOHAZARD UMBRELLA CHRONICLES Prelude to the Fall #2 is a manga published in 2007 alongside Resident Evil: The Umbrella Chronicles.
Picking up right where issue #1 left off, Chris Redfield accuses Albert Wesker of being the person responsible for the biohazardous outbreak. Wesker assures him and Jill Valentine that the outbreak was a mere accident, though doesn't go into the detail of explaining exactly what he was doing in the village in the first place. As a result of the explosion, part of the flour silo's floor collapses - Wesker uses this to escape with his superhuman powers.
Outside, three Hunter B.O.W.s appear in front of Chris and Jill. Wesker concludes that the Hunter Deltas must have been hidden underneath the silo. His plans changing to compensate for this unexpected event, Wesker escapes, leaving Chris to "handle" the situation. Chris however, is out of ammunition. The three head back to the hummer, allowing Chris to get out a grenade launcher to kill the Hunters with. Noticing what Wesker said of the village being "cursed", Anna remembers her father describing the village as such during the outbreak before handing her a pendant to protect her from evil.
Meanwhile, Wesker searches a house. The three survivors find Wesker as he moves towards a safe. He explains that the village was being used by Umbrella as a warehouse - should the companny fall, they will still possess B.O.W. and viral antibodies. He continues, claiming that the owner of the house was a member of Umbrella assigned to keep an eye on the warehouse. Wesker is here to steal Umbrella's research - the "treasure". Anna offers Wesker a pendant, which he judges to contain something of interest. He finds that, like other Umbrella items, it can be fasioned into a key. He tells Chris while unlocking the safe with the key that whatever caused the outbreak must be in it. Chris pulls Anna away just in time - the safe was booby-trapped. Anna's father knew someone would want to steal the data, and so gave the key to her, knowing that she would be forced into handing it over.
It is then revealed that Wesker has survived the explosion, but is now met by the Hunters, who he kills easily with his powers. He holds in his hand a disk he found elsewhere in Anna's house. Chris and Jill conclude that there is an Umbrella factory nearby producing the B.O.W.s from the warehouse...