After destroying Durandal's Core circuits, the Pfhor (presumably under Tycho's orders), have captured you and sealed you in a cell with the door guarded by two Enforcers. You are low on health and stripped of all your weapons and ammo... but you can still use your fists. Press your change weapon button to draw up your fists, use them to hit the closest Enforcer, then duck into the corner of your cell least visible from outside. Wait for the BOBs to teleport in and attack the Pfhor (this may take a bit of time, depending on the selected level of difficulty). From here you are teleported to This Side Toward Enemy.
- The phrase "Big House" is a nickname for prison... which is where you, the player, are.