Mothers' Instinct ending explained: Shocking spoilers for Jessica Chastain and Anne Hathaway film

To say that things become slightly unhinged from that point onwards would be an understatement, and as the film approaches its climax, several shocking twists and turns are sure to produce audible reactions from audiences.

If you've seen the film and need a recap of the events in the dramatic finale, read on to have the Mothers' Instinct ending explained.

Warning: contains full spoilers for Mothers' Instinct.

Mothers' Instinct ending explained: Shocking spoilers for Jessica Chastain and Anne Hathaway film

At the start of the film, Alice (Chastain) and Céline (Hathaway) share a close bond and enjoy a seemingly idyllic existence - but this being a psychological thriller, that was never going to last.

Right enough, everything dramatically changes one day when Céline's son Max tragically falls from a balcony and dies.

Alice had seen the event unfold from her garden and had attempted to prevent it but was too late in her intervention, something which leaves her with feelings of guilt – especially given that Céline seems to blame her for failing to avert the tragedy.

Although they initially appear to mend their relationship, Alice soon becomes paranoid that Céline is out for revenge and is targeting her family, suspicions which it turns out aren't unfounded – despite her husband Simon not paying much heed to the warnings.

This steps up a notch at the birthday party for Alice's son Theo, who had been best friends with Max, and in the time since his death appears to have developed a much closer bond with Céline.

At the party, Alice's outspoken mother – referred to as Grandma Jean – is suddenly found dead, and although the explanation provided is that she had forgotten to take her medication, Alice becomes convinced that Céline had something to do with the death.

As her suspicions increase and evidence starts to mount to suggest that Céline had been involved in Jean's death, Alice eventually discovers that Céline has been keeping a large supply of chloroform in a secret compartment of her house.

If viewers were left in any doubt about quite what was in the compartment, the chloroform is labelled in bright, clear letters – one of many moments in which the film doesn't exactly trade in subtlety.

Anyway, soon all hell breaks loose and Céline's revenge campaign – not to mention the film's camp elements – are ramped up to 11.

Céline and Alice have an encounter in the corridor where the former knocks the latter unconscious using the chloroform, while she also sneaks into Theo's room and applies enough so that he too passes out.

But she doesn't stop there: she then gases the house while Alice and her husband Simon are unconscious, killing them and making it look like a leak before taking Theo away. She's certainly holding nothing back.

The film ends with Céline being granted custody of Theo, with the closing scene showing them enjoying a day out at a beach – a wholesome image at odds with the scheming that has come before it.

Missing her own son and consumed by grief, Céline had become desperate to adopt Theo for herself – and did whatever was necessary to ensure that would happen.

And so she gets her happily ever after – even if most of the other characters aren't nearly so lucky...

Mothers' Instinct is now showing in UK cinemas. Check out more of our Film coverage or visit our TV Guide and Streaming Guide to find out what's on tonight.

Try Radio Times magazine today and get 10 issues for only £10 – subscribe now. For more from the biggest stars in TV, listen to The Radio Times Podcast.