On the trail of an Institute Courser the Sole Survivor must kill or be killed to gain access to the molecular array.
Returning to The Railroad with Virgil's information, Desdemona and Tinker Tom will send the Sole Survivor off to the ruins of C.I.T., where they will have to use their Pip-Boy's radio in order to detect a courser's recent teleportation signal.
Follow the radio signal east of the C.I.T. ruins, to a large bright green building. Upon entering, the Sole Survivor will run into a group of Gunners who will be aggressive, thinking that the Sole Survivor is yet another courser assaulting their men. As the Gunners are dealt with, and the Sole Survivor follows the trail of destruction left by the courser, they will finally reach the top floor, in which the courser will be seen ready to execute the Gunner's sergeant and a couple of his surviving men.
After killing the courser and obtaining his brain chip, it will be revealed that the courser was after a synthetic that had been kidnapped by the Gunners, and was being held hostage.
If Mama Murphy was provided with drugs, she can reveal Z2-47's reset code, allowing the player to eliminate him with minimal fuss.
Returning to Virgil, it is revealed that he does not have the equipment to decode the chip, and that the Sole Survivor must find someone with the proper equipment, with his advice being to follow the Freedom Trail. At this point, the Sole Survivor will need to decide as to which main faction to go to, in order to build the equipment needed in order to take advantage of this technology.
Travel to C.I.T.
Virgil has instructed me to travel to the old C.I.T. ruins and see if I can pick up a signal from a Courser using my Pip-Boy.
Tune to Courser's Radio Frequency
I need to tune to the Courser's Radio Frequency I picked up near the old C.I.T. ruins. With some luck the signal should lead me to a Courser.
Use the Courser's Radio Frequency to Track Courser
I have locked on to the Courser's Radio Frequency using my Pip-Boy. Now I need to follow the signal and find the Courser.
Kill the Courser
The signal led me to Greenetech Genetics in Cambridge. I now need to find the Courser, kill him, and recover the chip... no trivial matter according to Virgil. I should proceed with caution.
I have killed the Courser in Greenetech Genetics and recovered the chip.
Killing the courser does not provoke immediate hostilities from the Institute, yet many of its scientists, including Father, will on occasion mention their knowledge on what happened.