Does the Green Line work?
Through October 15th:
No service at Union Square (walk or take the 86/91/CT2 to East Somerville, or take the 87 to Lechmere) due to work on the Squires Bridge.
No service between North Station and Government Center (Haymarket is closed on the Orange Line too). Use the Winter Street concourse (within fare control, between Park Street and Downtown Crossing) and the Orange Line (between North Station and Downtown Crossing) to continue your trip.
This latest service disruption is jointly(!) sponsored by the Massachusetts Department of Transportation and HYM Investment Group.