I.

Idranel: Yes, the plans were correct. The forge's power supply is unstable. simple chain reaction will wreath this world in fire.
Warlock: Idranel - your wounds. The humans press in...
Idranel: Suffering and I are old friends, Warlock. See to the humans, and I will enact our final gambit to protect the Craftworld. My retinue's wards will keep me safe long enough.
Warlock: Of course, Idranel.

II.

Idranel: Remarkable... I had thought surprise lost to me... What a wondrous lesson [bad word] from such primitives... I wonder if the Bloody-handed God... will teach you anything in turn...
Tarkus: Why, witch?! Why seek to doom these worlds?! 
Idranel: You never asked yourself... where this Hive Fleet was bound for next... Unless we stopped it here... it would next feed upon Eldar. Surely even you can see... three human worlds... was a small price to pay to save a Craftworld...