Traders' War
The Traders' War by Charles Stross includes The Clan Corporate and The Merchants' War, the third and fourth instalments in the spellbinding The Merchant Princes series combined into one volume.
The journalistic instinct runs deep - and comes with a fatality warning.
Miriam was an ambitious business journalist in Boston. Until she was fired - then discovered, to her shock, that her lost family comes from an alternate reality. And although some of them are trying to kill her, she won't stop digging up secrets. Now that she knows she's inherited the family ability to walk between worlds, there's a new culture to explore.
Her alternate home seems located around the Middle Ages, making her world-hopping relatives top dogs when it comes to 'importing' guns and other gadgets from modern-day America. Payment flows from their services to US drug rings - after all, world-skipping drug runners make great traffickers. In a land where women are property, she struggles to remain independent. Yet her outsider ways won't be tolerated, and a highly political arranged marriage is being brokered behind her back. If she can stay alive for long enough to protest.
The Traders' War is preceded by The Bloodline Feud omnibus, and followed with the final volume, The Revolution Trade.