Coming after a spectacular arc, "D.P.O." would have to match huge expectations, but it plays out like an average MOTW from the first two seasons. It's not bad and is actually good in places, but it's hard not to feel letdown after the string of mythology.
"D.P.O." is also one of the more memorable episodes due to the performances by Giovanni Ribisi and Jack Black and the really cool lightning effects. Mulder and Scully are pushed out of the way, leaving the Darin and Zero to have their fun while they follow leads.
However, the episode takes a huge misstep in the plot involving Mrs. Kiveat. She's essentially a tool to end the episode, a simple plot device to bridge Darin doing cool things with electricity to a conclusion. Darin's fixation on her is bounded in looks, as her personality is flat as a board and hardly does anything other than be frightened. The ending is very awkward and confusing. Mulder and Scully stand around doing nothing, letting Darin take Mrs. Kiveat with him, and the episode ends when Darin is hit by lightning and locked up.
Score: 8.5/10