"They made us choose... they made us choose how we die."
- Dana to Marty in the elevator cube.
Dana Polk (Kristen Connolly) was a college student that went on a trip with her friends Jules Louden, Curt Vaughan, Holden McCrea, and Marty Mikalski to Curt's cousin's cabin in the woods. Her role was designated "The Virgin ." It is unknown what they chemically altered to make her more like her role.
Dana is the one that chose the Diary of Patience Buckner and read the Latin inscription that summoned the Buckner Family. After Jules is killed and Curt is persuaded to split the group into their rooms, she is attacked by Mother Buckner and Holden saves her. They go to the basement where the find the "Black Room," the room where the Buckner Family tortured people.
They are led out by Curt, who tells them that Marty did not survive, and together they try to escape in the RV. However, the tunnel is collapsed and when Curt tries to jump the canyon in his motorbike, he hits the forcefield and dies. Driving back to the cabin, Holden is stabbed by Father Buckner and the Recreational Vehicle crashes into the lake.
As the people in the control room celebrate, Dana is attacked by Matthew Buckner and tormented until Marty unexpectedly shows up and saves her. Instead of being killed, he found the elevator room where the Buckners were brought up and together they descend and find the glass rooms where all the monsters are kept. Once they are released into the facility, the guards are instructed to kill Marty first, then Dana. They hide in the control booth, where Dana finds the "System Purge" button and releases all the monsters. As they escape the carnage, Dana accidentally kills Gary Sitterson.
As Marty and Dana find their way to the sacrificial room, they meet The Director , who tells them that Dana must kill Marty in order to save the world. When Dana does point a gun at Marty, she is attacked from behind by the werewolf. After Marty shoots and wounds the werewolf and it runs off, the Director is killed by Patience Buckner, she shares one last joint with Marty and tells him that perhaps the world ending isn't so bad - now it's someone else's turn.
She presumbly dies when the Ancient Ones arrive.
Her characteristics, appearance and name all may be in reference to Dana Scully from The X-Files.