It was only a matter of time before Indonesian women and children were sacrificed as suicide bombers, a counter-terrorism expert and producer of a new documentary on the radicalisation of female migrant workers says.
But the events of 13 May still shook him.
A series of church bombings in Surabaya, East Java, were carried out by three families on motorbikes - including the country’s first women and children to blow themselves up. Twelve people were killed, along with all-but-one of the attackers; an eight-year-old girl. 
Just two months before, Indonesian filmmaker Noor Huda Ismail interviewed would-be female bombers for his documentary The Bride (Pengantin). Ismail, who is pursuing a PhD at Melbourne’s Monash University, had previously met an IS recruiter in West Java who said he was preparing a suicide bombing with his 11-year-old child in Syria.
A damaged motorcycle outside Surabaya Centre Pentecostal Church following a suicide blast. Source: Getty Images
"So I knew that something was brewing," Mr Ismail said.
"I knew that there is a specific cluster of the Indonesian community which is linked to ISIS who think it is ok to sacrifice their own kids for the cause of jihad.
"But I didn’t know when and how … When it actually took place in Surabaya, I could not really comprehend it."
The Syria bombing ultimately didn’t happen.
Pregnant and planning to attack
In the film, Mr Ismail - the founder of the Jakarta-based lnstitute for lnternational Peace Building - meets three Indonesian women living overseas who were searching for love online.
One found it, but the other two were lured by IS militants, persuaded to marry them and participate in terror financing and "amaliyah" (terrorist action). 
Dian Yulia Novi was married and working as a maid in Taiwan when she self-radicalised.
The film features two women who were lured by IS militants. Source: Supplied
"It was on Facebook … over the past year I was opening the Facebook statuses of jihadis, that was what inspired me," she says in the film.
I was opening the Facebook statuses of jihadis, that was what inspired me.
Aged 28 and nine months pregnant she was set to become Indonesia’s first female suicide bomber, or IS “bride”, in a plot to attack Jakarta's presidential palace.
"I decided to get married, I was given away by proxy, and my husband arranged our wedding," Dian says.
But in December 2016, the night before the planned attack, she was arrested in Bekasi, West Java with a 3kg bomb encased in a pressure cooker. She was sentenced to seven-and-a-half years in prison.
The plot involved a terror cell established by Indonesian militant Bachrun Naim. Her husband, Nur Solihin, also recruited and ordered by Naim to find a "bride", was additionally charged.
New Year's Eve plot
A few days after Dian’s arrest, another Indonesian woman Ika Puspitasaran was arrested for plotting a New Year's Eve suicide attack in Bali. She had worked as a maid in Hong Kong and been recruited on social media by IS. She was also involved in terror-financing.
She too had self-radicalised on social media and married an unknown hardliner from a West Java school in a long-distance ceremony.
"At that time, I was in Hong Kong, my husband was at an Islamic boarding school, so the one who married us was his religious teacher from the school. The vow happened later that night, so after finishing the ceremony I was contacted again," Ika says.
The women self-radicalised on social media. Source: Supplied
Family and neighbours were shocked. They describe both women as "normal and good".
What motivates these women?
The Bride is Ismail’s third film and follows his documentary about teenage IS fighters, Jihad Selfie.
He says while a string of terrorist incidents over the past month in Indonesia point to a wider spread of local extremist violence, attacks by whole families and their motivation has confounded experts.
"If we borrow the literature from cult movements, for instance, there are families who die for the cause," Mr Ismail said.
"Especially the belief this life is completely broken, unworthy – that there will be a good life after we die is not a new phenomenon."
But, said Mr Ismail, the goal of jihadis was to ensure a place in heaven by sacrificing their children.
Indonesians from different religious groups take part in a joint prayer for the victims of the Surabaya bombing in May. Source: AFP / Getty Images
"They believe they will be reunited in heaven. It’s horrible."
According to the Jakarta-based Institute for Policy Analysis of Conflict, 45 to 100 female migrants in Hong Kong were lured to ISIS between 2015 and 2017. Of six million Indonesian migrants, 78 per cent were women, World Bank data reveals.
The Bride addresses the problem of loneliness among such women, and the search for a sense of community away from home. Mr Ismail says Indonesia’s patriarchal society also plays a significant role in female radicalisation, "but jihadis are on a different level: the men dictate literally everything. Patriarchy in this context is beyond the normal family setting".
"These are not lone-wolves but packs of wolves who have been revived and expanded. In Surabaya they had their own network, they were waiting for the right moment to carry out an attack; they had been preparing for months."
The global premiere of The Bride (Pengantin) takes place on 28 June at Monash University, Melbourne.
