Return to Mirf who will ask you to slay Ayamia the Rat Queen. She can be found at ( 45, 0, -140 ) /waypoint 45, 0, -140. She's a rare spawn, so will need multiple room clearing to get her to spawn.
After killing her your journal will ask you to visit the Central Stairwell in Vermin's Snye at ( 120, 0, -109 ) /waypoint 120, 0, -109.
Next it will ask you to find the painting of the Coldwind Cliffs, located at ( 187, -7, -90 ) /waypoint 187, -7, -90.
After finding the painting, you will need to search and find the Sepulcher of the Prime Healer, located at ( 236, -7, -81 ) /waypoint 236.00, -7.00, -80.55. WARNING: If the undead that lurk in this area aren't gray to you, you may possibly be ambushed at this point with a group of undead.
Enter the sepulcher of the prime healer ( 237, -7, -81 ) /waypoint 237, -7, -81.
Finally, you must visit the Tomb of Lord Tonmerk at ( 252, -6, -119 ) /waypoint 252, -6, -119. At this point, you can click the tomb to zone in.