|Known ability||Acidic blood|
|Date of death||2007|
Mary Krause was an evolved human with acidic blood.
Mary is sedated in a room full of evolved humans in Building 26. Rachel Mills teleports into the room and releases Mary, Gordon Hovey and Eric Doyle. However before she has time to wake up she is shot by agents.
In chapter 10 of The Agent, Mary is sedated with a tube in her nose at Building 26 when Rachel teleports into the room and removes it, waking her up and two men next to her. Then, alarms go off and Mary begins to sit up, just in time to be shot and instantly killed by a couple agents who charge through the door. Her blood splatters across another bed, instantly burning through the sheets and flesh of the person lying on it.
In chapter 3 of Slow Burn, Chris and Gail Bowman hunt for The Watcher to find out how he knows about Mary. When they find him, he tells them they really would not want Samuel to find out what happened with Mary.
In chapter 7 of Slow Burn, Chris reveals to Bo the story of how the Bowmans had betrayed Mary. They were running from Building 26 together, but Chris devised a plan that had set Mary up to be captured but had allowed the Bowmans to escape. They later heard that Mary had been killed in Building 26, and have been keeping the story a secret ever since.
Mary's ability is to have blood that causes an acid-like burn. It is unknown as to whether the drug/gas being administered to Mary enhanced her ability.
- For other uses of Mary, see Mary (disambig).
Please refer to Theory:Mary Krause for fan-created theories and other speculation.