Naresh Trehan's writ ran unchallenged at the Escorts Heart Institute and Research Centre, the Delhi-based country's premium cardiac care hospital, till last week, when he and some senior functionaries close to him were shown the door by the hospital's owner, Fortis Healthcare.

Late this week, Trehan was re-instated following a Delhi High Court directive. And finally, the whole episode was dismissed as a "misunderstanding."

Trehan might be back in the hospital carrying out surgeries, but everybody now knows who calls the shots: Shivinder Mohan Singh. A scion of the Singh family of Ranbaxy and the managing director of Fortis Healthcare, he has emerged from the fracas as a man who will not tolerate larger than life employees.

The younger son of the late Parvinder Singh runs the country's largest chain of hospitals. (Older brother Malvinder runs Ranbaxy, though Shivinder is also on the company's board.)

He led the acquisition of the Escorts Hospital from the Nandas and later took Fortis Healthcare public. In the healthcare industry, he is known to be an aggressive player with very ambitious plans for growth -- Fortis has lined up investments of Rs 1,100 crore (Rs 11 billion) over the next five years.

Shivinder's dream project, of course, is the Medicity he wants to put up at Gurgaon on the outskirts of New Delhi. That is where the problem with Trehan began, who has his own plans to come up with a similar project at Gurgaon.

Shivinder knew that Trehan was one of the country's best- known doctors and his project was grand (It is worth Rs 1,000 crore (Rs 10 billion); General Electric, Atul Punj and others have committed to invest in it.) and unprecedented in scale in the country.

So he wanted both -- Trehan on his rolls and his project merged with that of Fortis. Trehan's ouster came after the failure of his 20-month long attempt to get him to agree for an operational relationship with Fortis in the Medicity project.

Frustrated by Trehan's refusal, Shivinder went public and charged Trehan of misappropriating funds and siphoning money into his Medicity venture. He also termed Trehan to be more of a businessman than surgeon. Trehan denied any wrongdoing. His patients mobbed the hospital in his support. Finally, the courts intervened and Trehan was back in the hospital.

For Shivinder, this was his first corporate skirmish. But those who know him well say that the incident is unlikely to slow him down. Like his father, he is a member of the Radhasoami Satsang of Beas (his maternal grandfather was the head of the community) and like him, is known to be a methodical worker.

Ten years back, when his father died, Shivinder, along with his brother Malvinder, had come out with a statement that he would have nothing to do with the running of the family business empire and would prefer to work his way up from the bottom, though their grandfather, Bhai Mohan Singh, was keen the two brothers be co-opted on the Ranbaxy board without any delay. As is obvious, the brothers took charge -- Malvinder at Ranbaxy and Shivinder at Fortis Healthcare.