On October 22, 2014, a man named Michael Zehaf-Bibeau entered Parliament Hill, killing Canadian soldier Nathan Cirillo and catching security off guard. On the 10th anniversary of what was later deemed a terror attack — and with security risks for politicians only growing — the Globe’s national affairs reporter, Kristy Kirkup, joins The Decibel to revisit the events of that day, sharing stories of responders, and explaining how Parliament Hill changed because of it.