Malazan Empire: Why are the Crimson Guard protecting Crockus ? - Malazan Empire

I have completely forgotton the reason for this. A friend is reading Gotm and calls me to disscuss topics as i have read upto Hoc. He has asked me "why did Brood send the Crimson Gurad to protect Crokus ? wasn't he on the same side as Rake at the time ?" I am unable to answer his question so i said i would post it here.