Earspoon can be found whispering to Borgus in the rear of Sharess' Caress. Approaching them triggers a passive DC 15 Historycheck (with Rogues and Baldurians having advantage) and a DC 10 Deceptioncheck or DC 15 Perceptioncheck to determine they are talking about Nine-Fingers Keene. The party can then ask Earspoon where Nine-Fingers is by passing one of the ability checks:
[PERSUASION] Come on, level with me. I'm not about to sell out another dwarf. (DC 15)
[PERSUASION] I bet a few coins would loosen your tongue. (DC 15)
[ROGUE] [PERSUASION] I'm looking to join the Guild. How about you point me the way? (DC 18 )
[FIGHTER] [PERSUASION] I need work, and it sounds like Nine-Fingers needs steel. (DC 18 )