After rescuing the female Krogan, both the Turian and Krogan delegates pull you aside to discuss separate missions that they need help with. Wreav informs you of a missing Krogan 
squad sent to investigate possible Rachni activity. This is disturbing as Renegade Shepard destroyed the Rachni Queen, supposedly the last remaining one, years ago.
Once on the planet of Utukku Shepard and crew encounter Urdnot Grunt, the tank-bred Krogan rescued from a lab a little while back. Grunt is leading a retrieval crew of his own. Shepard’s crew get’s separated and the two parties travel through a cave system. There they discover Ravager husks, indoctrinated Rachni. The crews must battle their way to the source and then back out, but the Krogan numbers are dwindling…
