Lily Bowen Lillian Marie Bowen is a nightkin living in Jacobstown in 2281 . Background . Born in 2079 , just two years after the Great War , Lily lived a simple life in Vault 17 - until the Master ' s army raided the vault . The 75 year old grandmother was dragged outside , where she saw the sun for the first time . Lily was then dipped in the vats of Forced Evolutionary Virus , emerging as a super mutant . She became one of the Master ' s elite guards , a nightkin , working sometimes as a spy or an assassin . After the fall of the Cathedral , she and her squad led by Tabitha eventually met with Marcus and formed a community at Black Mountain . When Marcus and Tabitha parted on less than amicable terms , Lily traveled with Marcus to to begin anew . Lily now tends to the bighorner s in the mutant community of Jacobstown . Like all nightkin , she struggles with her dangerous brought on by excessive usage , but is aided by Doctor Henry , who considers her to be a primary subject for medical testing in his personal quest to cure the nightkin of their affliction . Unbeknownst to Henry , Lily only takes her medicine in half - doses as it allows her to remember her grandchildren , a recording of whom she carries around on an old holotape . Leo . Lily frequently mentions someone named Leo , who seems to be the manifestation of her schizophrenia . She will have conversations and even arguments with " Leo , " insinuating that he drives her to do " bad things . " Leo ' s voice is audible to Lily only , but she experiences it as real ; " How else could I hear him tell me who to chop ? " In contrast to Lily ' s generally helpful and friendly personality , whenever she begins to exhibit violent tendencies , she will blame Leo . As it was mentioned by Doctor Henry , Lily is mad but not dangerous . Leo , however , is all about aggressive and sociopathic behavior . Leo is very fond of melee weapons . He is the one who tells Lily " who to chop , " and he will not be satisfied if Lily doesn ' t engage in melee combat on every opportunity she gets . If ordered to favor ranged combat over melee or to take a passive stance rather than an aggressive one , Lily ' s reply will be , " Well , if you insist . But Leo is not going to like it much ! " Lily also tells the Courier that Leo was the one who instructed her on making her Vertibird sword using parts scavenged from the Vertibird wreckage in Klamath back in west California . This weapon was built from the wreckage of a Vertibird previously flown and subsequently crashed by pilot Daisy Whitman . It is mentioned by Marcus that the nightkin suffer from schizophrenia induced by their prolonged use of Stealth Boys . During dialogue with Lily , the Courier may ask about the location of Leo . Lily replies by saying that he ' s right there by her side . The Courier may then try to convince Lily that there is no one there ( to no avail , of course ) . The creation of imaginary friends seems to be common among the nightkin , Davison takes his orders from a dead skull which he calls Antler , the unnamed nightkin that guns down Novac ' s brahmin every night , arguing with an unseen being , and Tabitha ' s radio show is nothing but Tabitha talking to herself as she alternates between her own voice and her imitation of the voice of Rhonda . Lily has to regularly take her medicine in order to " make Leo shut up , " and prevent him from taking over control of her body and going on a rampage in the process . If the Courier chooses to make Lily stop taking her medication , she will start to become more effective in combat but also more prone to psychotic rages , and , in the , she will be little more than a ravening beast . Lily and Leo ' s condition is similar to the one of Dog and God . Inventory . Additionally , Lily has a third companion weapon , a variant called Lily ' s gauntlet . This weapon is not initially in Lily ' s inventory , but may be given to her as part of a script which ensures all companions retain their special weapons . Lily is limited in the weapons she can use , and can only theoretically equip weapons from the following list . " Note : Lily ' s default assault carbine does so much base DPS that she will never equip certain weapons in practice ; these weapons are crossed out . " < section begin = " weapons " / > < section end = " weapons " / > Due to the above limitations , there are only two holdout weapons which Lily is capable of using : s and s . This makes Lily a less - than - ideal companion when performing quests which take place in " weapon - free " areas like the Strip ' s casinos . Appearances . Lily Bowen appears only in " " . Behind the scenes . Lily Bowen was written by Travis Stout .