Aribella "Bella" Tanios is the main antagonist of the Agatha Christie Poirot novel Dumb Witness, as well as the subsequent adaptation in the show Agatha Christie's Poirot. She's the niece of aging socialite Emily Arundell and an impatient and disgruntled heir to her fortune resorting to murder to hasten the inheritance.
In the film adaptation, she is portrayed by Julia St. John.
Biography[]
Bella Tanios is the daughter of Cambridge University professor Biggs and his noticeably younger wife Aribella Arundell. Bella earned a teaching position at a university herself to teach chemistry, and she eventually fell in love with Greek national and doctor Jacob Tanios and later married him, bearing two children with him (Edward-John and Mary in the book, Alexis and Katya in the film). Aribella Arundell's sister is Emily Arundell, a Victorian socialite and by the events of the story the last of her five siblings. With her inheritance comes all the wealth of the family, which Bella, along with her cousins Charles and Theresa, who are the children of Emily's other sibling, eagerly awaited once Emily was to die.
Book[]
Bella finally was fed up with waiting and wanting to take her children away from Jacob so as to not be domineered any longer. She planned to give her children a life they deserved with the money she'd inherit, so to hasten her plans, she decided to kill Emily and take the children with her once she secured the money. Jacob would be next so she'd be the only influence and provider of her children. Her first attempt was hammering a nail into the top of the stairs in the house and securing a tripwire so seemingly Emily would "have an accident" and die. She was severely injured, but she was never killed by the fall. But the family terrier, Bob, was framed for the fall, using his ball as a distraction and making it seem like what Emily lost her balance on.
Realizing she was in danger, she requested Hercule Poirot's services personally in a letter. Unfortunately, the letter was delayed in its arrival, so Poirot got the message weeks later. By then, Bella hastened her plans by siphoning out the weed killer of the gardener so she would employ the arsenic as her next weapon. She was motivated by Emily changing her will to leave her estate to longtime friend Wilhelmina Lawson. Being a chemist herself, she expertly converted the arsenic into elemental phosphorous, placing it in a capsule she disguised as a pill for Emily's liver problems. During a séance Emily attended with eccentric sisters Isabel and Julia Tripp, the poison took effect. Assuming "her spirit left", in actuality, the phosphorous let out exhaust in a green gas when she finally caved from the element, declining in her health and consciousness from there and dying days after the ritual. Poirot was too late to save Emily from death.
But he did investigate when he found glaring evidence of her murder: the varnished nail that pulled the tripwire taut, as well as Emily's letter mentioning her dog, who was on a picture of a jar so Poirot would recognize him, was out all night and couldn't have been playing with his ball, thus couldn't have tripped Emily. He eventually also finds the drained weed killer, which disproves resident doctor John Grainger's thesis that she died from her liver failure. Cousin Theresa Arundell seems suspect when dear friend Wilhelmina Lawson, Emily's friend who was staying in the house the night she fell, remembered seeing the initials "TA" in the reflection of the mirror, on the brooch of the assailant's robe.
Bella herself surprises everyone storming him and accusing Jacob of harassing her throughout her marriage. She finishes with saying Jacob is responsible for the murder and was planning to commit Bella to an asylum to keep her from testifying to it. She stays with Lawson, and Poirot instructs her to go to a hotel and read papers he prepared for her. Bella was shocked to find out Poirot wrote in full description her crimes and how he figured them out. Overcome with the terror of facing judgment for her actions, and conceding that she'd never have her children, she burned the papers and then committed suicide by the chloral hydrate she planned to kill Jacob with to keep her kids. It's unknown if Poirot intended for the collateral damage of her death. Eventually, he brings the family together, reveals her as the killer and all her plans leading up to her death. He realized from discerning Lawson saw "TA", but in a reflection. The letters in the actual order were "AT": for Arabella Tanios. If she stayed alive, she would've found out Emily wanted to change her will back, but Lawson lied and said it was already at the lawyer's office, assuming she decreased the inheritance for her friend and Lawson wanted it like that. Out of guilt as well as affection for a family she knew for years, she split the inheritance with the remaining heirs. Hastings takes Bob in as his own dog.
Agatha Christie's Poirot[]
In the series adaptation, Bella started to resent and be embarrassed by Jacob when, while in England, he merely imitated his surroundings for his family's success instead of putting in his own labor to bear earned fruit for his family. Finding Jacob "weak" from his placating demeanor in his life, and shocked he wants to take his family to Greece so he won't be stymied by xenophobic prejudice to be successful, Bella, with her resentments, was longing even more for the inheritance. When she couldn't take waiting any longer, she started devising plans to discreetly kill Emily in hopes before more time was wasted, she and cousins would be sole heirs to the family fortune. She started pretending a ruse where she "became increasingly frightened of" Jacob and having the lie of him "beating" their children as a diversion and part of her plan.
With Captain Arthur Hastings visiting Charles as a close friend, Poirot's already there by the time Bella screws in the hook to fasten the tripwire to. She doesn't tie the wire that night, because family terrier Bob gets out of his bed seeing what she's doing. When she's taking him back, Wilhelmina Lawson, who's sleeping in a room Bella passes by, sees her robe and her holding Bob, but not her face. She tells Bella to put Bob back in his basket so no one else wakes up. There she remembers seeing "TA" on the robe. In the morning, when everyone's gone downstairs except for Emily, Bella fastens the tripwire, knowing she's the only person who'll be wounded by the trap. It works and Emily sustains serious injuries when she's done rolling down the stairs. The family rushes to save her, and she's given medical attention just in time, but she stays in bed from being too battered from her fall to walk. Bella set up the scene when she got there as well by getting rid of the tripwire and screw and leaving a ball at the bottom of the stairs to frame Bob. Poirot sees through this: Bob has a signature trick of dropping the ball down the stairs and catching it in his mouth. He always places the ball in his basket afterwards, meaning it's not his nature to leave it around and thus absolving him of his guilt.
Poirot himself visits Emily and encourages her to change her will, suspecting one of her relatives is responsible. Bella already hastily makes more plans to make another attempt on Emily. Continuously making points of Jacob's outbursts and saying bruises in her son Alexis' back are from Jacob's beatings, she takes a bottle of vitamins that she gaslights Poirot into believing are poisoned as part of his abuse, even though it isn't tainted in the least. The phosphorus she poisoned Emily with is in her liver pill bottle in fake capsules. Emily walks out in the garden that night, and that's when the Tripp sisters rejoice from witnessing the green smog exit her mouth before she dies then and there on the walkway.
The would-be heirs are horrified by Emily's new will leaving Lawson the estate, leading to Charles and Theresa stealing valuables, but fleeing on boat when a portrait of General Arundell falls and wakes Lawson. But that's not what spooks Bella. With everyone already thinking Jacob poisoned Emily, Dr. John Grainger recognizes the symptoms of her death as phosphorus poisoning from the green haze. Calling Bella, he inquires for Jacob and when he can't reach him he asks Bella if Jacob has phosphorus handy. Fearing Grainger will soon discover the truth, Bella sneaks into his room and causes coal gas from a heater to leak and poison Grainger to death so he'll be silenced.
When Bob barks at his reflection in a boat, Poirot figures everything out. He assembles all the suspects and witnesses and reveals the vitamins were harmless, Charles and Theresa were the thieves, and the poison was in Emily's liver medicine bottle. But when he reveals Bob's trick with the ball and Bob barking in the mirror, he goes to the final incriminating evidence. Lawson saw "TA" but in a reflection. Demonstrating with the letters written on a card, he reveals the initials are really in the order of "AT": Aribella Tanios. Bella, wide-eyed, is demanded by Jacob if she's the killer. She shrilly, literally points the finger at Jacob, citing his temper that makes him suspect. But reiterating the circumstantial evidence and her guilt, Bella just silently scowls and caves, slowly and quietly lowering herself into a chair. When Jacob asks why, she says he hates him, that he caved to people around him and she would've lost her life and caring for kids moving to Greece. She voices how much she begrudgingly holds in contempt over not receiving a penny for bettering her living quality, even noting her cousins could've done the same. She then turns to Poirot and sneers he made a worse decision making Emily change her will. Poirot simply says her cold heart deserves no mercy, before she's arrested. Poirot encourages Lawson to share the inheritance with the Arundell descendants, and Bob is taken in by the Tripp sisters.
