Love story of two people who don't quite fit

Hampstead is based on the true story of Harry Hallowes, an Irishman, who in 2007 won squatters’ rights to a half-acre plot of land on Hampstead Heath, worth £2 million, because he’d lived there for more than 12 years.

Keaton plays Emily Walters, an American widow living in a flat overlooking the heath, and struggling financially. From an attic window, she spots Donald Horner (Gleeson) being attacked in his shack - and goes to find him. What ensues is a sweet and funny love story, as two people that don’t quite fit in take solace in each other.

Keaton’s iconic Annie Hall look - buttoned up shirts and scarves, and trouser suits with top-pocket handkerchiefs - can be seen in the film, although, as she says, it’s a “little more conservative”.

“The costume designer, Liza Bracey, the sweetest woman ever, toned it down, which was important, but also, I did want to be that fish-out-of-water. I didn’t want to look like the other women in the movie, because they were all proper and well-to-do and wealthy, ‘the club’ ... and I wanted me to be the person from America who was, you know, just not really quite right.”

‘The club’ is led by busy-body block of flats resident Fiona, played by Lesley Manville, who lends Emily money but pressures her into supporting her husband’s company’s bid to develop the land Donald lives on.

Compared to Emily, the group of ladies-who-lunch in her building seem completely disingenuous, but Keaton disagrees.

“She was just as guilty of being disingenuous herself. She took her money, she pretended like she liked her ... not OK. That’s why I was really interested about her relationship to these people, where she was never honest, didn’t stand for much of anything and kind of going along... Every bit as bad as everyone else.”