You are unable to secure a mount or similar transportation to travel to Isondale, however; you are able to get in touch with Perras Highdancer, a local halfling that works as a fencer for the black market. He operates out of his jewelry shop as a cover for his more nefarious jobs. After spending an excessive amount of time and gold on persuaded him to talk to you, much less open up the black market to you, he finally gives in. He allows you access through a cellar in his business which opens up into ancient caverns that run below Dewbreak. in these caverns are vendors that setup daily to sell various items ranging from slaves imported from Mordredia, magic items of a vile nature, drugs, rare "pets", and many other things. Perras explains that the black market has been operating out of the caverns under Dewbreak for about fifty years, and the tunnels themselves lead both to Isondale, and deeper into the underdark. The vendors use the tunnels to move between Isondale, Mordredia, and other locations in secret. Prior to being allowed entry you are sworn and told that if you break that secrecy you, and those you love will see a fate worse than death.   You are able to convince Perras that it is in his best interest to allow you to inform your adventuring friends of this place and establish a "partnership" with Perras as the representative for the black market. He is able to provide you with a basic (common) prosthetic limb for a highly discounted price of 20gp's. He also suggests that he might call upon your group in the future when he needs assistance. Perras mentions that he has previously dealt with Fip and trusts him. He also mentions that he is aware of Erik's dealing with Vinnad Humblefoot and Vinnad reports that those dealings have gone well.