Authors note: I am still working on Too Late Now. This is just something that came to me last night.
In the five year since the Battle of Five Armies Billa and Bofur corresponded regularly. Although their correspondence was hindered by the fact that Bofur's reading skills were atrocious, so much so that he had Bifur read them to him, for although Bifur could no longer speak westeron he could read it quite well and read it he did.
Their correspondence was so regular in fact that when two moons passed without a letter from the hobbit-lass both Bofur and Bifur began to feel uneasy. Perhaps they had offended her in some way? They chastised themselves heavily for their imagined slight until one day when a distressed Ori came to see them.
"Have ye heard from Billa lately? I know you two are the only others who correspond with her. Have you had a letter? I haven't in two months and I'm becoming very worried" Ori was yanking his braids through his speech, a sure sign of his concern.
Bifur and Bofur looked at each other in alarm. Why had they not thought to ask Ori? Perhaps they had been wallowing in self-pity and loathing when their Hobbit was in distress.
"Well?"
"No lad, we haven't"
"Something must be wrong, very very wrong"
"but what?"
"We'll just have to find out then, shan't we"
And so Bofur, Bifur and Ori started planning a second quest. One that did not encompass a dragon but which they faced with as much dread as if it did, for only a terrible occurrence would stop Bilberry Baggins from writing to her Dwarrow.