Then came Day 369, when the couple was biking in formation with a group of other tourists on a panoramic stretch of road in southwestern Tajikistan. It was there, on July 29, that a carload of men who are believed to have recorded a video pledging allegiance to the Islamic State spotted them.
A grainy cellphone clip recorded by a driver shows what happened next: The men’s Daewoo sedan passes the cyclists and then makes a sharp U-turn. It doubles back, and aims directly for the bikers, ramming into them and lurching over their fallen forms. In all, four people were killed: Mr. Austin, Ms. Geoghegan and cyclists from Switzerland and the Netherlands.
Two days later, the Islamic State released a video showing five men it identified as the attackers, sitting before the ISIS flag. They face the camera and make a vow: to kill “disbelievers.”
It was a worldview as diametrically opposed as imaginable to the one Mr. Austin and Ms. Geoghegan were trying to live by. Throughout their travels, the couple wrote a blog together and shared Instagram posts about the openheartedness they wanted to embody and the acts of kindness reciprocated by strangers.
