For those who need help in which way to go next to find there monsters for there next quest just follow the red line and avoid the purple which means theres ACEs in the area...oh and the blue is pit bosses avoid at any lvl unless ur lvl 40+ :)

-note- by the time you get to crawlers corridor you dont need to go further cos your monsters are in solus from now on

i hope it helps
K3 - Bulky Lunker Aces
N3 - Argholquich Aces
U16 - Grumble Hook Aces
O14 - Grumble Hook Aces, Rigor Lapis Aces
U19 - Rigor Lapis Aces
K14 - Big Ratmoth Aces
K8 - Frenzy Ratmoth PitBoss, Big Ratmoth Gaurds
Q20 - Arghol Drone PitBoss, Arghol Guards
F18 - Splinter Rex PitBoss, Splinter Guards
H16 - Warbeast Keen PitBoss, Warbeast Guards

Source: RFBase.com