[X] The Tailless feels Love for its dead kin still. You have the Loop of Loops, the neck-hanging Treasure that is all that now remains of one of them, and you remember their Last Song as a pattern of sigils, lines and curves. Perhaps you could offer up the Loop of Loops and the scribbles that dead Digger made...?
[x] The Tailless has acid! A liquid that eats through wood and stone and smells like that- That is definitely acid. You need to get some to rescue Volt. Somehow. Then again, there are other ways you could try to free Volt.