In episode 10x3 Supergirl makes her public debut. Only it is not Kara and this Supergirl brings a misdemeanour from Clark's past into the light.
The X-Men's task was simple. Prevent Apocalypse's escape. They failed. Now they face having to stop a foe of near limitless power before he can enact his plans for both the world and a certain Last Son of Krypton.
For months the X-Men have heard tell a prophesy of a great dark power on the horizon, about to rise and now his time has come. Can the X-Men stop his rise or will the world truly tremble once more in the presence of Apocalypse?