From Golden Light They Come

Instead of placing them on the battlefield,
ADEPTUS CUSTODES INFANTRY,
BIKER or DREADNOUGHT unit from
your army in a Godstrike-pattern
teleportarium array for 1 CP,
or two such units for 3 CPs.
At the end of any of your Movement phases
these units can teleport into battle anywhere
on the battlefield that is more than 9" away
from any enemy models.
This Stratagem can only be used once.