One of the Ghosts depicting the gleam.

The Blue Gleam is what happens when The Ghosts are under an emergency. This particularly happens when Pac-Man uses the Power Pellets to consume them until he reaches another Critical Mass. It was invented by Jehova in order to save The Ghosts in case something happens, his original plan being that they kill Pac-Man. However, Pac-Man found out this weakness and Jehova granted The Ghosts with reincarnation in order for them to infinitely chase Pac-Man until the end of time, having to replace them when a Critical Mass event hits.