An Ambush of Widows by Jeff Abbott

Henry North is a down-on-his-luck cybersecurity expert from New Orleans. Wei "Adam" Zhang is the cofounder of one of Austin's most successful venture capitalist firms. These two men didn't know each other. They had never met. Yet they died together, violently, in a place neither had any business being, leaving behind two widows.

Kirsten North is a 30-year-old consultant for the tech sector, when one day, Henry doesn't return from a business trip. Kirsten panics—and then gets an anonymous phone call: Your husband is dead in Austin. When she frantically searches for information, she finds the days-old news about the murdered millionaire and the unknown man found with him.