She was a beautiful, haughty actress, only in her mid-thirties but already closing on the twilight of a glorious career in the movies. She was lonely, closeted with her novels in a sprawling Madras bungalow. Her domineering mother was dead, the men in her life had faded away. Bar one. Her co-star, lover and mentor, now already a political giant on the Tamil Nadu stage, was blithely nudging her into public life. It was at this time she was introduced to, and befriended, the owner of a small video-rental facility who would bring her tapes of old English classics to fill the empty hours.

J. Jayalalithaa had met Sasikala Natarajan.

The two would forge an intense, complex, often inexplicable, bond that is still making big headlines out of Chennai. Jayalalithaa is dead; Sasikala looms over her casket, feeding on its aura to fashion an all-new political ambition - yesterday's chinnamma (little mother) already in the process of overshadowing Amma.

How did this come to be, a casual acquaintanceship alchemised into a full-blown political legacy?

It was a thing of dogged and patient crafting. Looking back, many veterans of the Dravidian movement are convinced Sasikala and her husband, M. Natarajan, a government employee, worked hard at what's now coming to fruition.

An early insight: When MGR, as chief minister, learnt from intelligence sources that Sasikala was warming up close to his "Ammu", he called Natarajan and warned him to stay away. Natarajan repaired from the admonishment and turned it into a weapon. A former Jaya TV employee revealed to The Telegraph: "Sasikala used that incident to stoke Jayalalithaa's insecurities and fears - party leaders were against her." The Natarajans soon brought men from their hometown Mannargudi to guard her; they were known as the Grey Cats. In the name of protecting her, they actually began to isolate her. "The couple started manipulating her with an eye on power, and though Natarajan, a dominating character who played a lot of politics, was thrown out mid-way, what they wanted has finally come to pass," he told us.

Today, not even a month after her akka's (elder sister) burial, Sasikala has already slipped into Jayalalithaa's big shoes as AIADMK boss, and could well become chief minister, shaking off O. Panneerselvam, himself beholden to her.

So who is Sasikala Natarajan? She was born into a lower middle-class agricultural family in Thiruthuraipoondi, 330 kilometres from Chennai, near Thanjavur. Her family, which belongs to the Kallar community, a sub-caste of the powerful Thevars, settled down in Mannargudi town. A school dropout, she married Natarajan, a government employee. She was rustic, childless, but ambitious. She opened a video rental shop which would also undertake shoots of weddings and other events. Having shot Jayalalithaa's speech at the AIADMK's Cuddalore conference, and a dance drama she did for another function, Sasikala badgered her husband to take her to meet Jayalalithaa so she could personally gift her the recordings. Once she stepped into Jayalalithaa's precincts, Sasikala never stopped going. By the time Jayalalithaa became CM in 1991, she was entrenched in her Poes Garden home.

Thereon, she became central to an audacious period in the political history of Tamil Nadu marked by corruption scams, opulent displays of wealth, jail terms, nepotism, back-room manoeuvring, and even a failed coup to topple Jayalalithaa (on which she was tipped off by Narendra Modi and the late satirist and political writer Cho Ramaswamy.)

By 1996, Sasikala had not only taken charge of Jayalalithaa's home, but also her financial affairs - she was signing cheques for Jaya TV and was co-owner of her huge summer home in Kodanad in the Nilgiris. She was the one who dealt with political leaders and the rank and file of the AIADMK: Chinnamma, Amma's alter ego.

Having graduated to becoming a partner in her business ventures, Sasikala also ended up being the co-accused in a number of corruption cases like the Rs 8.3-crore colour TV scam, the Tansi land case scandal, and in the disproportionate wealth case, which is still in the Supreme Court.

Jayalalithaa, always a recluse, was happy with this arrangement. "It suited her. She did not have to get her hands dirty directly, Sasikala did everything for her," says Pala Karuppiah, former AIADMK MLA expelled in January this year for denouncing politicians and bureaucrats for looting the public.

However, Jayalalithaa did try to distance herself from Sasikala twice. Once in 1996, she publicly denounced her after the AIADMK election debacle. But Sasikala remained loyal to her friend and though she was arrested during M. Karunanidhi's rule, she did not turn approver. Karunanidhi did try to drive a wedge between them. He criticised the fact that a woman from a backward community was taking the rap for someone's else acts. Sasikala begged her companion to take her back and even landed in hospital from jail to get Jayalalithaa to her bedside. Jayalalithaa relented.

The second time Jayalalithaa threw out Sasikala and her band of relatives was in 2011. Nobody knows the real reason, but it was seen as a purge. However, Sasikala wormed her way back after penning an emotional letter. "Not even in my wildest dreams I have thought of betraying Jayalalithaa... I have no ambitions either in the party or the government... and anyone who conspired against akka will remain persona non grata to me," she wrote. Jayalalithaa took her back; Sasikala systematically crushed those who had turned against her during her exile from Poes Garden. "She can be very vindictive," says the former Jaya TV employee.

The chief reason Sasikala is disliked by the AIADMK cadre is that she has placed relatives and loyalists from Mannargudi in key positions. Her family of three brothers and a sister and their brood have all benefited from Sasikala's special bond with Jayalalithaa.

Her brother's wife, Ilavarasi, lived with her at Poes Garden along with her son Vivek, who nurses political ambitions and handles businesses like their new acquisition, Jazz Cinemas. Nephew T.T.V. Dinakaran, a former MP, enjoys her backing. Another nephew, Sudhakaran - the one Jayalalithaa adopted briefly and conducted a lavish wedding for, and later banished - was back around her body during the last rites.

Theories abound on what kept this pair together - power, money, insecurity, greed, need, all of that? "Jayalalithaa was temperamental, only Sasikala took everything she meted out quietly. On the other hand, Jayalalithaa was a willing victim of Sasikala's machinations and knew what was going on around her," says a senior DMK politician.

Speculation forever swirled over a relationship between the two. The theory was spurred when they participated in the Mahamaham festival at Kumbakonam. In this festival, husbands and wives take a dip in a holy water tank to pray for each other's longevity. Jayalalithaa and Sasikala took the dip and garlanded each other; tongues wagged but who's to tell the truth?

Sasikala looks poised to take over as chief minister of Tamil Nadu. But politicians, bureaucrats and political analysts remain sceptical about how she'll fare. Especially because she isn't as well liked - much less revered - as Jayalalithaa among the cadres. And she hasn't a proven mass appeal.

"Sasikala's image is of a behind-the-scenes person. She has never come on the political stage before. But her money power will speak. The party is going along because it has no choice right now," says a former election commissioner.

Karuppiah has little faith in her ability to lead. "Everyday, she would ask Jayalalithaa what she would like for lunch. It seems Jayalalithaa never discussed policy issues with her because Sasikala has no idea of the issues facing people," he says.

Sasikala cannot be compared to Jayalalithaa, she was just her companion, says R.S. Bharathi, senior DMK leader, adding, "In that case, Shanmuganathan, who has assisted Kalaignar (Karunanidhi) for 50 years, should lead the party. There are so many questions before her for suppression of facts regarding Jayalalithaa's hospitalisation. The court has also expressed doubts. Jayalalithaa was trapped in an emotional bond with these people. We have to wait and see how Sasikala will perform. But, her ultimate test will come when she has to face the people and contest elections."

At 60, Sasikala has come a long way to reach where she has; ahead of her lies a longer road.