Deathwing by William King, David Pringle, Neil Jones

and
     those
     powers
     that
     are
     better
     not
     named.
     And
     we
     knew then
     - they
     were renegades, survivors
     from the
     Age
     of Heresy
     who had
     pacted
     with
     Chaos
     in
     exchange
     for
     eternal
     life. The
     fighting
     became
     close
     and
     heavy.
     They
     had
     the
     weight
     of
     numbers,
     but
     we
     had
     our
     Terminator
     armour
     and
     the strength
     of righteousness.
    "For a moment, it looked as
     though
     they
     might overwhelm us,
     but
     then
     our thunder
     hammers and
     lightning
     claws
     came into play, and
     we
     cut through
     them
     inexorably.
     They
     fought
     like
     daemons,
     and
     they
     had
     the
     strength
     of
     the
     damned, but
     eventually
     we won.
     
     

    "I stood
     looking down at the
     body
     of my last foe, and
     a thought
     occurred
     to me: this
     man
     had
     once
     been
     a
     Marine
     like myself. He had undergone
     the
     same training and
     indoctrination
     as
     I had. He
     had
     sworn
     to
     serve
     the
     Emperor.
     And
     yet he had
     betrayed
     humanity. How could
     this
     be?
    "How could
     a true Marine become forsworn?
     It seemed unlikely that
     he would suddenly
     turn
     his back on the
     pattern
     of a lifetime and
     pact
     with the
     Darkness.
     What
     had
     Chaos
     to offer him?
    "Wealth?
     We have
     no use
     for the
     baubles
     that
     other
     men covet;
     we
     already
     have
     the
     finest
     of
     everything
     that a
     man could
     wish
     for.
     Sensual
     gratification?
     We
     are taught
     its
     transitory
     nature.
     Power?
     We
     know
     true
     power,
     which
     is
     the will of the
     Emperor. Who
     among us
     could
     equal his sacrifice?"
    "No
     -
     as
     I
     stood over
     his
     body
     I
     came
     to
     understand.
     He had
     deviated
     not
     in
     one
     leap
     but
     in
     small steps,
     by increments.
    "First
     he
     had
     come
     to
     place
     trust
     in
     the
     Warmaster.
     An
     easy
     step,
     for
     was
     not
     Horus
     the
     chief
     champion
     of
     the
    Emperor?
    "Then
     he had
     come to follow the
     Warmaster. Who
     would not? A soldier follows his commander.
    "Then
     he had
     come to
     believe
     Horus
     divine.
     An
     easy
     mistake.
     Was
     not
     the
     great
     Heretic
     one
     of
     the
     Primarchs
     of
     the
    First Founding,
     gifted with god-like powers
     second
     only to the
     Emperor himself.
    "Thus
     did
     he
     sway
     from
     the
     path
     of
     truth,
     till
     eventually
     he
     lost
     both
     his
     life
     and
     soul. It
     is
     a
     way
     that
     is
     open
     to anyone,
     one
     small mistake leading to another
     until at last the
     Great Error
     is
     reached.
     This
     I
     came
     to
     realise
     as
     I studied the
     body
     of the
     renegade
     on the
     Prison of Lost Souls. I resolved
     then
     and
     there
     to
     submit
     myself
     to
     the
     Emperor's
     will. I knew that
     all
     our
     regulations
     and
     our codes
     have
     a purpose,
     and
     it
     is
     not
     for
     us
     to question
     them,
     for
     they
     keep
     us from the
     path
     of the
     deviant.
    Around
     the
     fire, there
     was silence. Cloud Runner could
     tell that
     Bloody Moon's
     words
     had touched a
     chord
     within
     the Marines.
     He found
     himself examining
     his
     own conscience
     for signs
     of
     heresy.
     The
     implication
     of
     Bloody Moon's
     tale was
     quite
     clear:
     if
     they
     lapsed
     from
     the
     service of
     the Emperor,
     they
     were
     taking
     the
     first step
     down
     the
     road
     to damnation.
     He
     had
     also
     reminded
     them
     that
     they
     were
     Marines,
     the
     chosen
     of
     the
     Emperor.
     If
     they
     did
     not
     keep
     the faith, who would?
    For a long time, all was quiet. Then
     Weasel-Fierce indicated
     his wish to talk. "I