What happens after you witness something you can't get out of your mind?

Today on Now or Never, stories from the bystanders, and how their lives changed in the aftermath.

Trevor asks strangers on the street to share the most memorable thing they've ever witnessed, from northern lights to Beyonce sightings.

As a kid growing up in Barrier Lake, Quebec, Shannon Chief has a vivid memory of coming across 12 moose in the woods one cold wintery night, "like grandfathers standing around me." Today, seeing a moose in the wild is rare. As Shannon and elders witness the animal’s decline, they’ve banded together to take action to stop sport hunting in a Quebec wilderness reserve.

Marla Minshall has been supported by friends and family all their life. Now they’re looking for a chance to do the same for others - by serving as a witness at strangers' weddings.

Darrell Warren is determined to fight crime in his neighbourhood. At 64 years old, he’s voluntarily staking out suspected drug houses in Winnipeg’s North End, and starting a tip line so other community members can come forward as witnesses. But is it safe?

When Ti-Anna Wang was 13, her father — Chinese pro-democracy activist Dr. Wang Bingzhnag — was charged with terrorism and espionage and sentenced to life in prison in China. Much of Ti-Anna’s life has been spent advocating for her father’s freedom, but today she’s ready to embrace a new chapter.