Clifford DeVoe was Keystone City's district attorney. He failed to get a conviction of mob boss Hunk Norvock, and this failure, coupled with the knowledge that crime could be made to pay, drove him to alcohol. He joined Norvock's gang. Soon, however, Norvock became jeslous of DeVoe, and tried to kill him, but only succeeded in killing himself. DeVoe took over his gang and began to call himself 'the Thinker'. He developed a 'thinking cap', a metal hat that could project mental force to use in his crimes.
He soon came into conflict with Flash (Jay Garrick) and was arrested by him many times. He joined the Injustice Society. He also fought the Huntress, Power Girl and the Atom.
