This ground-breaking two-part documentary profiles extreme relationships that have never been portrayed on British TV before. The second instalment looks at women who are sexually and emotionally attracted to objects. These so-called ‘objectum sexuals’ shy away from contact with other humans in favour of structures large and small. The film follows Naisho, an American woman who has ‘married’ the Eiffel Tower and is in love with the Berlin Wall.

In San Francisco, 37-year-old Naisho stands proudly in front of the Golden Gate Bridge. “I am a woman and this is a bridge. And despite our vast differences, we are very much in love,” she declares. For Naisho – whose real name is Erica – being in love with a bridge represents many difficulties, not least the fact that she cannot be alone or intimate with it. “I curse myself for being human,” she tells her lover. “I wish I were an object like you.”

Naisho is part of a small group of people known as ‘objectum sexuals’ or ‘OS’ people. There are only 40 declared OS people in the world and all of them are women. Objectum sexuals exhibit passionate feelings for inanimate objects and project personalities onto their lovers. Many of them are in love with multiple objects; aside from her bridge, Naisho is ‘married’ to the Eiffel Tower and has even changed her surname to ‘Tour Eiffel’. She maintains a physical relationship with a piece of fence in her bedroom and in the past has formed lasting attachments to a sword and a bow. Her affinity with her bow, ‘Lance’, led her to become a world-class archer.

But why do Naisho and other OS people prefer cold, hard objects to living human beings? Naisho suspects her sexuality has its roots in her traumatic childhood, when she was molested by her halfbrother and abandoned by her parents. After living in different foster homes, Naisho endured a difficult spell in the military, and was eventually released from service on psychological grounds. “If I am the way I am today because of everything that happened to me, then I’m all right with it,” she says. “I wouldn’t change who I am now.”

The film follows Naisho as she travels to New York and then Berlin, where she visits another powerful object of her affection – the Berlin Wall. Naisho’s passion for such a controversial structure – a symbol of repression and pain to many Germans – leads to an uncomfortable encounter with a member of staff at the Checkpoint Charlie museum, which is dedicated to chronicling the wall’s bitter history.

Reflecting on the journey she has made, Naisho says that she sees parallels between herself and the Berlin Wall. “I just don’t understand how some people can bring someone into the world like a child – an object – and then not love them,” she says. But the wall, she adds, has taught her how to stand up and be herself. “I am the Berlin Wall. Hate me. Try to break me apart... but I will still be here, standing.” A reinvigorated Naisho completes her trip with a visit to Paris to be reunited with her beloved tower on the first anniversary of their marriage.

Elsewhere, the documentary profiles Amy, an objectum sexual in New York, who currently holds a torch for a fairground ride and a church banister. Like Naisho, Amy has a dysfunctional family history and has turned her back on relationships with men. Diagnosed with Asperger’s syndrome – a type of autism – Amy has had to fight suicidal impulses in a bid to come to terms with her sexuality and the discrimination she faces.

However, with the support of Naisho and other OS people, she is able to express her feelings more openly. “Now that I have you and the rest of the community,” Amy tells Naisho, “the world can’t stop me.”