Umbrald Mines

From publisher blurb: This quest is suitable for a party of 3 to 4 players of 3rd to 4th level. Welcome to the Umbrald Mines! This quest will take your players through a wonderouse mine loaded with gems that are sought after by the rich and powerful. Sadly now crew have strated to go missing and Snigg Iornbelly now looks for adventures to resuce the miners lost and get his mine back into working order. Is it just an act of misfortune or is there a bigger plot at play in these mines?