Burning Cover

Burning Cover is a Railroad side quest in Fallout 4. It is the aftermath of failing Underground Undercover and being branded an enemy of the Institute, which also fails all other active, related Railroad quests.

Detailed walkthrough
This quest is fairly straightforward and only requires talking to two people.

The Sole Survivor has blown their cover, and must speak to Desdemona for the next step. When talking to her, she explains that there is little hope for rescuing any synths now that communication with Z1-14 is lost, and that the Railroad numbers are too few to challenge the Institute directly. She instructs the Sole Survivor to work with the Commonwealth Minutemen, as they are the only army capable of forcibly freeing the synths. Desdemona also thinks they might be able to find another way into the Institute with the data found in the network scanner holotape.

The next step is to talk to Preston Garvey. Depending on how far the Sole Survivor has advanced in the Minutemen storyline, he will react differently, but ultimately he will agree to support.