Mara tells Paul she needs a fancy dress and a gun. When she appears in the reverie, she is wearing the dress but not carrying the gun or even a purse. When she talks to Rachel, both her hands are empty, yet similar to how the Angels on Charlie's Angels (1976) were able to produce guns while wearing bikinis, she produced a gun and ganked the 4 gun thugs.
When the correct pronunciation of "Vater" is pointed out, the V sound used is as in English "vase". In fact, the correct pronunciation is "FAH-ter". German V sounds like English F except in a few words such as "November".