Abby and Martha Brewster

"He was such a lonely old gentlemen, mister Minchly was."

- Martha Brewster "All his kids and kin were dead."

- Abby Brewster "We felt so sorry for him."

- Martha Brewster "And then when his heart-attack came and he sat there, dead, in that chair, looking so peaceful - Remember Martha? We made up our minds then and there that if we could help other lonely old men to find that same peace, we would."

- Abby Brewster

Abby and Martha Brewster are two central antagonists in the stage-show and movie Arsenic and Old Lace. The two sisters are villains by proxy who commit twelve different murders which they see as mercy kills.

Premise
Arsenic and Old Lace starts off with Mortimer Brewster, a famous stage critic getting married in secret to his long-time love Elaine Harper. Hounded by paparazzi, he quickly signs the legal papers to be wed without any formal ceremony and then rushes out, intent on stopping by the house of his aunts, Abby and Martha, who raised him. At the Brewster home, Abby is entertaining Elaine's father and trying to make the wedding more appealing to him, as a reverend the notion of a non-ceremonial wedding alone bothers Harper but additionally he is somewhat over-protective of his daughter. While entertaining Harper the police officer Grosby and new recruit O'Hara come-by to pick up donations to charity. Martha arrives shortly before the three leave to introduce herself. Abby and Martha introduce their nephew Teddy Brewster to O'Hara (and the audience). Teddy Brewster believes he is US president Theodore "Teddy" Roosevelt and has since he was young but as his delusion has never hurt anyone and his aunts take care of him Grosby and the neighbors in general have been largely tolerant of him, other than the bugle he blows whenever he climbs up the stairs, believing the stair-case is San-Juan hill.

Once their guests leave Abby tells Teddy "There has been another Yellow Fever victim." At which point Teddy goes to get his shovel. Martha seems well aware of what Abby means and after Teddy leaves asks if she had any trouble without her. Abby reveals she was able to handle herself but there was no time to make the move and points to the window-seat. As the two are about to check, Mortimer arrives and the two greet him. Abby and Martha take a break to make Mortimer at home. While the two are in the kitchen, Mortimer discovers a body in the window-seat, believing at first that Teddy had finally suffered a full psychotic break he goes to Abby and Martha to tell them he needs to be committed. Abby tells Mortimer that the man was not killed by Teddy but by her - further more he is just the twelfth such man and she and Martha have been killing men for quite some time. The first man they ever buried was a man named Mr Minchly, who they had welcomed in for tea but who was otherwise entirely alone with no friends or family and extremely unhappy. Minchly had a heart-attack where he sat. When Teddy saw Minchly dead, he assumed he was a Yellow Fever victim and went to bury him in Panama (the cellar). Abby and Martha thought he looked so peaceful after his last few days of unhappiness that they made-up their minds to give anyone else they happened to meet with similar friendless, lone lives a similar death. Abby and Martha set-up a sign in-front of their house saying there was room for rent, if any lonely men came in the sisters saw it as their civic duty to put and end to their misery. The two had devised a method of poisoning, Martha had perfected just the right balance of poision by going into the old home-lab of Moritmer's father and taking a small amount of arsenic, strychnine and cyanide to a gallon of wine. Just enough to quickly kill the drinker without being able to be tasted in the wine. Each time they would tell Teddy the man was a Yellow Fever victim and Teddy would help dispose of the body by dragging it "down to Panama" and digging it a grave, where his two aunts would preform last rites and sing hymns over the grave before burying him.

Mortimer realizes his aunts mean well but also that they are a public menace. When they leave to make dinner he devise a plan to stop them without harming them. Mortimer decides that if Teddy were gone, neither of his aunts could continue with their method as neither had the strength to move men down-stairs and dig graves. Teddy was also well known to be delusional so he could convince a mental-ward very easily to take him and since Teddy was harmless he would neither be ostracized nor punished severely, just locked in a secure location with many professional live-in aids. Upon working out his plan Mortimer immediately starts calling the local sanitarium. Elaine, goes in to check what is keeping Mortimer. Mortimer tells Elaine something has come-up and they will have to wait to go on their honey-moon and shoos her out of the house while he makes his arrangements. While Mortimer is on the phone a renter named Gibs comes in to ask about the room. After some brief introductions Gibs reveals he hasn't got any family or friends and the sister invite him to dinner, getting a specially set-aside beaker of wine. After a stress-filled time setting up appointments on the phone, Mortimer comes over to grab a glass of wine, Abby subtly indicates the wine is not for him, at which point Mortimer realizes that Gibs is about to become the thirteenth victim, drops the wine glass and chases Gibs out of the house.

Mortimer tries to make his aunts understand what they are doing is wrong, but it seems lost of them. He is able to make them promise to not do it again though. With Elaine still waiting outside Mortimer realizes he owes her some explanation of his stress and the time he has spent inside and goes out to try to apologizes for seemingly ignoring her on their wedding-day. Teddy moves the body, while Abby and Martha prepare for the services. While the family are out two men enter the house, Johnathan Brewster and his physician "doctor Einstein". Johnathan was Mortimer's brother, he was also a fugitive murderer, who had escaped the police. As he was in the area, Johnathan decided to use his old family home to hide-out for a while. Abby and Martha encounter the two and ask who they are; The question provokes Johnathan's anger at Dr. Einstein, who's facial surgery of Johnathan was so radical that apparently event his own aunts did not recognize him. Realizing who Johnathan was, Abby and Martha, agree to allow him to stay the night but say after he must leave. While Abby and Martha go to discuss the matter, Dr. Einstein asks what to do about the body they are carrying with them of Johnathan's latest victim, Johnathan opts to hide it in the window-seat at the moment, then the two go upstairs to get settled.

When Mortimer gets back in and goes to check on the victim he sees a brand new one. Mortimer confronts his Aunts about breaking their word to him and killing someone else. Though Abby states they had nothing to do with the latest body Mortimer does not believe her.

"Aunt Abby how can I believe you? There are twelve men down in the cellar and your admit you poisoned them."

- Mortimer Brewster "Yes I did. But you don't think I'd stoop to telling a fib!"

- Abby Brewster

Abby states she and Martha had always wanted to do a double funeral, but she refuses to sing hymns over a total stranger. Once Mortimer finds out Johnathan has returned he realizes his aunts are innocent of the latest crime and uses it to black-mail Johnathan into leaving. This however only provokes Johnathan into attempting to murder Mortimer.

The Third-Act of the play has to do with Mortimer trying to evade Johnathan's attempts at murder while maintain his plans to have Teddy committed and keeping the police away from his aunts. In the end, Johnathan is arrested, the bodies in the basement are kept hidden and Teddy is committed to Happy-dale sanitarium. Abby and Martha don't want Teddy to be stuck alone in some privatized half-way-house and plead to be allowed to go with him. In the end Mortimer insists that the sanatorium humor them and allow them. Though the director states they do-not accept sane people, Mortimer is able to pass his aunts off as boarder-line senile and all three are scheduled to be sent off to Happy-dale. Even if it is later revealed that the two were murderers, with their mental-health accounted for as compromised Mortimer knows they can not legally be locked up for murder. When Mortimer signs the commitment papers as next-of-kin, Abby asks if they will investigate the signatures, Martha tells Mortimer he is not really a Brewster. The two reveal his mother had come to work for the Brewsters as a live-in cook, but was already pregnant at the time. Abby, Martha and Mortimer's father found Mortimer's mother to be kind and didn't want to lose her so Mortimer's father married her. Johnathan was in-fact to blood-related to any of them. Both sisters insist that blood doesn't really mean anything he would always be family as far as they were concerned. Apart from being upset, Mortimer is ecstatic that he is not blood related to any of them as madness appears to run in the family. Mortimer leaves his aunts to prepare to leave with Teddy and the sanitarium director as he goes off to his honey-moon with Elaine.

Personalities
Abby and Martha both have the outwardly mannerisms of a kindly-old couple of sister. Both believe murdering otherwise miserable men is a form of charity, relating it to the likes of donating cloths or putting rooms cheaply up for rent. Abby is the more social of the two, and Martha is inquisitive, Abby tends to do the formalities while Martha mixes the poisons. Abby and Martha are religious Protestants and sing hymns and give last rites. Despite being traditional Protestants they make no discrimination over religious differences and treat all their victims them same. Both woman are exceedingly honest and refuse to tell a lie. They view the fact they have twelve bodies buried in their cellar are just a puckish little secret hobby. As demonstrated with Johnathan's victim, they two are not overly eager to see others dead, and refuse to sing hymns over a man they never even met. This seems to add to the fact the two suffer an advanced form of delusion and to outright psychopathy.