Once Bonnie Anne reaches Level 8, she summons you to a Tavern and leads you on a quest promote her;
Once you've spoken to her she tells you to go speak to Ol' Fish Eye (the Musketeer Trainer) and ask him about the Scaramanga Musket.
He then tells you that a Cutthroat Lackey stole it and you should go "sort him out" to retrieve it.
After defeating him, the Lackey tells you that they left Adulphos' Scaramanga at the Corsair's Cove.
You find the Scaramanga deserted on an island, broken, so you take it to Lucius Fox in the Gullet to repair it.
Lucius manages to fix it up nicely for you and you should go celebrate in a tavern cellar!
