From May 24 through Sept. 2, customers will be able to purchase one-way tickets between Boston and Hyannis for $20, and round-trip tickets for $35, a Massachusetts Department of Transportation and MBTA statement said. The DOT, which will operate the rail service in conjunction with the Cape Cod Regional Transit Authority, said it hoped the return of swift public transit will draw tourists to the Cape and reduce pollution.

...

On Fridays, one train on the Middleborough and Lakeville line will leave South Station at 5:12 p.m. and make the roughly two-and-a-half hour trip to Hyannis, then embark on a return trip at 8:30 p.m. On Saturdays and Sundays, the train will leave South Station at 8 a.m. and return from Hyannis at 6:30 p.m., the statement said.