Underground Undercover

Underground Undercover is a quest and achievement/trophy in Fallout 4.

Quick walkthrough
Infiltrate The Institute and meet with The Patriot.

Quest stages
1. Talk with Tinker Tom 2. Upload Encrypted message on any institute terminal 3. Read Patriot's reply 4. Meet Patriot 5. Follow Liam 6. Talk to Liam 7. Talk to Desdemona 8. Enter report on terminal 9. Talk with PAM 10. Get password for code defender 11. Return to Desdemona 12. Meet with Z1-14 13. Give password to Liam Binet 14. Give Z1-14 a day 15. (Optional) Deposit weapons for rebels 16. Kill tunnel guards 17. Return to Z1-14 18. Continue working for father

Bugs

 * It is possible that Desdemona will not initiate dialogue when trying to warn her about the brotherhood.
 * This may be caused by Glory being dead. To fix go to Railroad HQ and use recycleactor 000508EE and 000508EE.moveto player in the console.