It happens only in India, goes a Govinda song.
And these words never seem truer than when applied to Bollywood.
But, even by the unpredictable standards of the Hindi film industry, this incident stands out for brazenness.
It happened in early 1970s when Amitabh Bachchan, who was struggling for a foothold in the industry, signed a potboiler titled Duniya Ka Mela.
The film was directed by Kundan Kumar; a little-known name today, but a biggish gun in the 1960s and 1970s. He helmed musical hits like Ganga Maiya Tohe Piyari Chadhaibo (1962, India's first Bhojpuri blockbuster), Aulad (1968, the Jeetendra-Babita starrer best-known for the comedic song Jodi hamari jamegi kaise jaani), Pardesi (1970, a slinky Mumtaz dancing to Chitragupta's hit tunes) and Anokhi Ada (Jeetendra-Rekha's first hit together).
In 1973, before Zanjeer put Amitabh Bachchan on the road to megastardom, Kumar cast him in Duniya Ka Mela alongside Rekha.
Distributors advised the film-maker against what they saw as a foolhardy move. And they were only being rational. At that point, Bachchan had featured only in films like Saat Hindustani, Pyar Ki Kahani, Bombay To Goa, Parwana and Gehri Chaal -- some of which were superflops.
In the last two, he had played villainous roles and was seriously thinking of trying his luck as the anti-hero, a la Shatrughan Sinha.
But Kundan stuck to his guns.
He even shot a romantic duet, Yeh chehra yeh zulfen jadoo sa kar rahe hain, composed by the hit-makers Laxmikant-Pyarelal with his lead pair.
This is when the distributors threatened to back out of the project.
They advised Kundan Kumar to get rid of the wobbly semi-newcomer and replace him with someone more box office-friendly.
Bachchan was sacked overnight and not even informed properly of his loss. He was replaced by the then hot and saleable Sanjay Khan (who dropped his surname in his films's credits).
Sanjay had delivered a slew of successes in the late 1960s and early 1970s.
But look at Destiny's devious ways!
By the time Duniya Ka Mela was released in 1974, Sanjay Khan's career was on the downside and Bachchan, after Zanjeer, was the rising star who would rule the industry for decades to come.
The duet from Duniya Ka Mela, a miserable flop by the way, was re-shot with Sanjay and Rekha.
Technically, Duniya Ka Mela is the first film that paired Amitabh Bachchan and Rekha on screen, although the one that released first with them in the lead was Do Anjaane in 1976 (where believe it not, Rekha elopes with Prem Chopra after marrying Amitabh Bachchan).
Recalling that experience, Bachchan says he holds absolutely no grudges. "I was grappling with flops. I was grateful that they even considered me for the film. I was replaced by Mr Sanjay Khan who was a big star during those times."