Upon entering, the first sublevel consists of a small room with some broken elevators to the south and stairs to the north. There are some feral ghoul and raider corpses littering the area. Also to the north, near a raider body, is a trip wire trap hooked up to a makeshift bomb attached to a trash can. There are two ammo containers near another raider corpse hidden behind some debris.
Going down the stairs brings one to the second sublevel which opens into a larger room with restrooms to the southwest and southeast, countertops with registers to the west, east and north, and stairs down at the northwest and northeast. There are live feral ghouls on this level; one hiding in the east restroom, one will crawl out from the west register area, and two reside near the west stairs. There is also an Expert locked door on the north end of the room which leads behind the counter and to a protectron with a Novice terminal and the Live & Love #2 on top of a safe.
One can go down either set of stairs to reach the platforms below. Taking the east set of stairs leads to a platform with at least 4 feral ghouls roaming the area. From the bottom of the stairs there is a Novice locked utility room to the south and access to the tracks to the north. A feral ghoul can be found to the far north end of the tracks feeding on a raider corpse with the journal scrap. Taking the west set of stairs leads to the opposing platform with another 4-5 feral ghouls wandering around. To the north is a small hallway followed by an Advanced locked door, both of which lead to a storeroom where a leveled feral ghoul awaits along with a steamer trunk of loot and the College Square Station key. To the south of the stairs is another protectron and pod with a Novice terminal and access to the tracks.
Picking the lock at the ticket counter will make the protectron hostile to the player character. (Only if it has already been activated; it will be friendly if its terminal is hacked after the door is open.)
Upon returning to this location, everything will reset/respawn except for the dead raiders. Their bodies will be gone, leaving only their dropped weapons.
While investigating the corpses in the lower levels, Codsworth may remark "looks like these raiders became quite the Feral feast."