You can get the Cipher Rod from The Labyrinth
From Fractured Ingress, Go to the left to this portal and wait until it displays the scenery shown in the image below. Once that happens, go through it.
You will fall through a bridge and proceed to the next area.
You will reach an area teeming with enemies, where the Cipher Rod can be found at the base of a statue.
McCabe can use Cipher Rod to create the Enigma Handgun.
