City negotiators and the transit union sat down with a federal mediator for several hours Saturday in hopes of ending the OC Transpo strike.
Neither side will report specifics, but the talks are expected to continue Sunday - day 12 of the work stoppage.
Christmas carolers tried to warm hearts on Saturday during a cold day in Ottawa's ByWard Market, with the chill almost symbolic of the state of relations between the two sides in the strike. But the return to the bargaining table had many transit users telling CTV Ottawa they were optimistic.
If a deal comes, OC Transpo buses probably won't be running until late next week. There would be limited service for the first two days before the system is fully operational, according to the city. Union members would also have to ratify before drivers and mechanics return to work.
The decision to return to the bargaining table came after a Thursday meeting between O'Brien and union vice-president Randy Graham.
With a report from CTV Ottawa's Kate Eggins
