amin ▁co ck tail ▁with ▁radio active ▁iron ▁as ▁part ▁of ▁a ▁secret ▁government ▁study . ▁Mary lou ▁was ▁one ▁of ▁the ▁patients ▁who ▁was ▁given ▁the ▁co ck tail ▁in ▁ 1 9 5 3 . ▁Though ▁she ▁did ▁not ▁know ▁this ▁until ▁years ▁later , ▁the ▁effects ▁of ▁the ▁iron ▁caused ▁her ▁to ▁develop ▁several ▁health ▁problems . ▁In cluding ▁for ▁her ▁daughter , ▁Helen , ▁to ▁die ▁from ▁cancer ▁at ▁only ▁eight ▁years ▁old . ▁ ▁Once ▁she ▁gets ▁to ▁T alla has see , ▁Mary lou ▁goes ▁by ▁the ▁pseud onym ▁Nancy ▁Arch er ▁from ▁the ▁film ▁Att ack ▁of ▁the ▁ 5 0 ▁Foot ▁Woman , ▁and ▁moves ▁into ▁a ▁house ▁on ▁the ▁edge ▁of ▁Dr . ▁Spr ig gs ' ▁neighborhood . ▁But ▁she ▁soon ▁disco vers ▁that ▁Wilson ▁is ▁now ▁suffering ▁from ▁de ment ia , ▁and ▁has ▁been ▁re located ▁there ▁to ▁live ▁with ▁his ▁daughter , ▁Caroline . ▁Dec iding ▁she ▁needs ▁a ▁new ▁approach , ▁Mary lou ▁be fri ends ▁Caroline ' s ▁daughter ▁and ▁Wilson ' s ▁young est ▁grand child , ▁Su zi , ▁and ▁soon ▁gets ▁to ▁know ▁the ▁rest ▁of ▁the ▁family . ▁She ▁then ▁dec ides ▁that ▁instead ▁of ▁killing ▁a ▁man ▁who ▁no ▁longer ▁members ▁his ▁cr imes , ▁she ▁should ▁ru in ▁his ▁entire ▁family . ▁ ▁It ▁turns ▁out ▁that ▁Mary lou ▁will ▁not ▁have ▁to ▁make ▁much ▁effort . ▁Caroline ▁is ▁going ▁through ▁a ▁mid - life ▁crisis , ▁and ▁is ▁est r anged