Reprints X-Men #12 and #13
"The Origins of Professor X"
So starts the tale of Charles and his step-brother Cain, aka the Juggernaut. Charles tells the story of Cain and their rivalry as children as Cain stands outside of the School, taunting the X-Men. No matter what they throw at the Juggernaut, it's not enough to stop him as he finally reaches Xavier.
"Here Walks the Juggernaut"
The battle with the Juggernaut continues as the X-Men manage to delay him to give Charles the time to create a new tool to amplify his metal abilities. Charles reaches out to other super heroes for help using his new device as his X-Men try to stop the Juggernaut. The Professor uses Johnny Storm (the Human Torch) and his X-Men to finish off the Juggernaut.