Master Neotar?

[Spark]

I was reading in another post that once you kill Driller, you talk to Master Neotar and ask about a special weapon. Afterwards, a self-loading crossbow will appear in the lever factory. I can see the option of asking about a special weapon before I fight Driller......problem is, once I kill Driller, Master Neotar is nowhere to be found and all I get in my inventory is some other weapon I have no use for. Am I missing something? I'd love to have the Arbator for my archer army. Any help would be appreciated.