The Railroad safehouse at Ticonderoga has gone dark, their last report mentioning a lone Courser operating in the area. As the Coursers are usually harbingers of doom, Desdemona asks the Sole Survivor to investigate...
Talk to X9-27 to learn that the Institute learned of the safehouse and hit it, hard. They are currently in a holding pattern, waiting for any Railroad operatives and synths to wander into their trap.
Kill everyone. Make your way down the stairs to the ground-level exit. Kill another Courser outside.
Coursers have been spotted in the field, which means trouble. Desdemona has asked me to check on Ticonderoga Safehouse, which has gone dark. Hopefully the Institute hasn't found them.
200
Kill all Coursers
The worst has happened. The Institute has wiped out Ticonderoga Safehouse, all hands lost. Now it's my job to clean them out. There can be no survivors.
300
Report back to Desdemona
With all the Coursers eliminated, what's left of Ticonderoga is secure. I should let Desdemona know what happened here.
400
I reported the bad news to Desdemona. We lost Ticonderoga Safehouse and High Rise. Now we're in a race. Can we free the Synths before the Institute wipes us out?