Bruce chuckled. "Oracle likes to quote this cartoon mouse about doing the same thing every night," he told her, slowing down the speed of both videos to compare them more minutely.
And a variance flickered in the Riddler version, so quickly, he almost missed it. "Hold on," he murmured. Backtracking through the frames he saw the Riddler holding up a sign with a word written on it. "Upon," he read out loud.
Pulling up two more screens, he wrote down the word and played the video at normal speed to see at which point the word appeared, the wrote down the time. "They've added in frames," he explained to Dinah. "Like subliminal messaging. A single frame would appear too fast for the brain to process at normal speed, but slowed down..." Bruce tracked forward in both videos, frame by frame, until he saw another anomaly. Harley held up a sign this time, showing the word "a".
Marking it again, he played the third video to mark the point in the song and noticed something else. "Freeze Frame - it's a command. If I'm right, each word in the clue appears every time the lyrics repeat the words 'Freeze Frame'." Testing the theory, the scanned forward again and found Riddler giving them the word "score".
"There we are," he said, and proceeded through the rest of the song.