|Unmarked Quest: Learn about Vault City and education from Mrs. Bishop|
|Have 9 Intelligence, 6 Charisma or 6 Strength.|
|Ask Mrs. Bishop about Vault 13 or G.E.C.K. and leave conversation.|
|Accept her drink offer... and have sex with her.|
|Ask her about Vault City.|
|Open her wall safe and take the Pip-Boy lingual enhancer.|
|Reward: 500 XP, Pip-Boy lingual enhancer|
Ask Leslie about Vault 13 or G.E.C.K. (either option is unavailable if you already found it) and end the conversation. She will offer you a drink (if you have 6 Strength or 6 Charisma). After you accept, she and the Chosen One will end up in her room. Have sex with her. Speak to her in bed about Vault City (requires Intelligence 9). She'll explain that she lived in Vault City and someday met Mr. Bishop, he opened the wonderful world of drugs to her, but when Vault citizens found out about it, they kicked her out and she had nowhere to go but to join Mr. Bishop. She took the Pip-Boy lingual enhancer with her when she left Vault City. If asked, she will give the Chosen One the code to her safe (used through the Lockpick skill on the safe) where the enhancer can be found hidden in a secret compartment.
Without going through the aforementioned dialogue options, you won't find the lingual enhancer inside the safe.