Kristen Bell and Jonathan Groff are set to reunite in the original musical Molly And The Moon

Kristen Bell and Jonathan Groff will appear together on screen again in the upcoming original musical film Molly And The Moon.

The new musical is set to be written and directed by the How I Met Your Mother creators Carter Bays and Craig Thomas, Deadline reported on Thursday.

Both Bell, 40, and Groff, 35, have previously collaborated in the hit animated Disney films Frozen and its sequel.

New project: The movie will be written and directed by the How I Met Your Mother creators, Deadline reported Thursday; shown in August 2019

Together again: Kristen Bell, 40, and Jonathan Groff, 35, will star in the original musical film Molly And The Moon, to be written and directed by the How I Met Your Mother creators, Deadline reported Thursday

Although the film is described as a musical comedy, it also includes dramatic elements inspired by Thomas’ difficult experience as a new parent during the early years of How I Met Your Mothers’ successful run on CBS.

The writer recounted how he and his wife were expecting their first child, a boy named Elliot, in the period when he and Bays were working as showrunners in seasons two and three.

‘I was heading into parenthood and I figured everything was going according to the life script I imagined for myself. I’m going to have this healthy, perfect kid and come back and keep running that show. Instead, life served up an enormous curveball to us,’ Thomas recounted to the outlet.

‘We discovered after he was born that Elliot had Jacobsen Syndrome, a rare genetic deletion where a piece of one of the 11th chromosomes has broken off, resulting in the loss of certain genes that go into making a healthy, typical baby.’

Tough times: The film includes dramatic elements inspired by Thomas' experience as a new parent in the early years of How I Met Your Mothers' run on CBS; Bays (L) and Thomas in 2016

Tough times: The film includes dramatic elements inspired by Thomas’ experience as a new parent in the early years of How I Met Your Mothers’ run on CBS; Bays (L) and Thomas in 2016

Scary: Thomas' son Elliot was bone with Jacobsen Syndrome and required multiple open-heart surgeries and weeks in the hospital; shown in 2012

Scary: Thomas’ son Elliot was bone with Jacobsen Syndrome and required multiple open-heart surgeries and weeks in the hospital; shown in 2012

‘And what it meant for Elliot is that he had several heart defects and needed open-heart surgery at only two weeks old, and we did not see any of this coming,’ Thomas continued. 

‘And all of a sudden, we are living this completely different story line than we had imagined for ourselves, our son going through open heart surgery at 2 weeks old. 

Thomas’ son also weighed less than four pounds, complicated her chances of survival. 

The writer worried first that his son might not survive his intensive surgeries, and even if he did, he would be ‘a kid who was different, who might have lifelong health and developmental issues. Those two journeys are so intense for anyone to go through.’

The two collaborators began to think about how Elliot was experiencing his early health struggles. 

‘He was having a more mythic, epic journey that I had in my three decades of life, all in his first couple of weeks of life,’ Thomas said. ‘Carter found himself wondering too, what is that little life going through in this plastic box? What is Elliot thinking and feeling as he’s lying there?

‘You hear phrases like, “Oh the surgery went well but he’s not out of the woods yet,” and we would wonder, what are the woods like, and how would you show them?’

Old pals: Bell and Groff have collaborated on both Frozen and Frozen II, as well as in short films from the franchise; pictured in 2013

Old pals: Bell and Groff have collaborated on both Frozen and Frozen II, as well as in short films from the franchise; pictured in 2013

TV star: The actress has made a name for herself on acclaimed shows including The Good Place, Showtime's House Of Lies and Veronica Mars; pictured in February in NYC

TV star: The actress has made a name for herself on acclaimed shows including The Good Place, Showtime’s House Of Lies and Veronica Mars; pictured in February in NYC

Eventually, Thomas and Bays realized that Elliot’s story could form the basis for what would become Molly And The Moon, and the child’s journey home at the end of weeks in the hospital cemented the idea.

In the film, the child inspired by Elliot has been renamed Molly Moon, and Kristen is set to play her mother Kate, while Jonathan will star as Molly’s father Brian.

Both have proven their singing skills in the two Frozen films, and Groff is also a Broadway star, best known for playing one of the lead roles in Spring Awakening and appearing as King George III in Hamilton, both of which earned him Tony nominations.

Bell has been prolific in recent years, starring in NBC’s well-reviewed metaphysical comedy The Good Place, and before that starring in Showtimes House Of Lies from 2012–2016 and the modern detective series Veronica Mars from 2004–2007.

She returned to playing the sleuth in a 2014 movie and a fourth and final season for Hulu in 2019.

Groff’s TV work includes stints on Glee and the lead role in HBO’s drama series Looking, as well as its follow-up film.

He also appeared as the lead investigator in the critically acclaimed crime drama Mindhunter, which was led for two seasons by director David Fincher.