At various points throughout The Darkness 2, main character Jackie Estacado will relinquish control to his limey compatriot, the Darkling. During the past several preview events featuring next year's Digital Extremes-developed Darkness sequel, said Darkling has been a part of the environment, wantonly assisting in the murder of Jackie's foes but not allowing himself to be commanded.
In a preview session this past week in Manhattan, however, I was shown how one specific Darkling section will play out in the final game. After somewhat stealthily winding Jackie through a dingy brothel, he arrived at a brightly lit area (which can't be accessed due to his dark powers) with a conveniently placed Darkling-sized ventilation shaft just above the door. Moments later, and I'm inside the Darkling, piloting him through the vent and out into a new area.
I was told that these sections are scattered throughout the game, allowing for limited, context-specific Darkling action sequences (read: you can't use him whenever you want). The emphasis during his brief scene was on puzzle solving, allowing Jackie to progress through the door -- the Darkling had to navigate bright lights (which hurt him), enemies with guns (bullets hurt, too), and unknown corridors to find the solution. Sneaky Darkling pilots can pounce on unsuspecting enemies from behind, quietly murdering the bad guy and allowing for an escape.
After a few more moments of sneaking around, I disconnected the light's power source with the Darkling and was instantly zipped back to Jackie, thankfully skipping an unnecessary trek back through where I had just come from. Unfortunately for Jackie, however, the demo was just about to end, which meant he was moments from being trapped by the forces out to steal his powers. Maybe next time, Jackie boy!