A Psyker's fate takes a dark turn as he finds himself hooked up to a strange, similar copy of the same orb that five Space Marines of the Retributors Chapter are approaching right now.
These two orbs seem to be communicating with each other without the Psyker or the Space Marines acknowledging it, their purpose ominous and unclear.
When the Psyker tries to warn the two high-ranking Space Marines of the Retributors Chapter with him that the "free" orb is going to attack them, the other orb reacts, sending a shock through the Psyker that leaves him twitching spasmodically.
Meanwhile, as the ritual the Inquisitorial agent is conducting goes awry, the Captain Brother wastes no time.
With a swift, decisive motion, the Captain Brother punches the Psyker's head off, and the Space Marine with him immediately opens fire on the corpse, pumping four shots into his body.
This way, the Psyker's powers surge out of control, and before anyone can react, he is killed in a brutal fashion by his watchers: the two high-ranking Space Marines of the Retributors Chapter.
Most other humans would need only one bolter blast to be reduced to fine mist, but in this universe, such measures are often the most efficient form of mercy.
This might seem excessive, but in the grim darkness of the 41st millennium, it is a bare minimum precaution.