For six months, a county in Nova Scotia, the province, and the whole country have wondered: what happened to Lilly and Jack Sullivan?

The six and five-year-old siblings were reported missing from their Lansdowne Station, N.S., home in rural Pictou County on May 2.

The children’s family has told media — and police, according to court documents — that the brother and sister wandered away that morning.

Here are some key updates in the investigation:

Children reported missing

The family reported that six-year-old Lilly and then-four-year-old Jack had left their home on Gairloch Road in the early morning hours of May 2.

The children’s stepfather, Daniel Martell, told Global News that Lilly and Jack were home that morning with him, his partner and their baby. When they noticed the children were missing, he said the family immediately ran outside to look for them.

Police launched an extensive search involving agencies from across the region — by ground, air and on water — using search and rescue volunteers, drones, police dogs and helicopters. The search covered four square kilometres of heavy-wooded rural terrain.

Six days in, RCMP said they were scaling back the search because the likelihood the children were alive was “very low.”

“We’re not packing up and we’re not giving up,” Staff Sgt. Curtis MacKinnon, District Commander for Pictou County District RCMP, said on May 7.

The provincial government has offered a reward of up to $150,000 for information that leads to the children being found. The disappearance has been added to the province’s Major Unsolved Crimes Program, which the province says is a “tool to help police in major unsolved crime cases.”

Polygraphs and pieces of blanket

Police confirmed Lilly and Jack were last seen in public with family memberson May 1 based on eyewitness accounts and video evidence.

Court documents released in August included initial impressions by police of polygraphs given to Martell and the children’s mother, Malehya Brooks-Murray.

RCMP conducted at least four polygraphs during their investigation. Martell’s polygraph “indicated he was truthful.” The test for Brooks-Murray found she was truthful when answering specific questions, although the list of questions is redacted in the document.

An unidentified investigator’s comment included at the end of a section on the results of both of those polygraphs says, “At this point in the investigation Jack and Lilly’s disappearance is not believed to be criminal in nature.”

The documents also confirmed that investigators found a second piece of a pink blanket that belonged to Lilly in the trash. The first piece was found a kilometre from the family home in a tree on May 2.

On May 4, another piece of blanket was seized by police after it was found inside a trash bag at the end of the driveway of the children’s home, according to police.

In a June update, RCMP said “all scenarios are being considered.”

There were 11 units working on the case, including the Behavioural Sciences Group and the Criminal Analysis Service, in addition to the National Centre of Missing Persons and the Canadian Centre for Child Protection.

“We’re committed to doing what is necessary to locate Lilly and Jack and advance the investigation, which may take longer than we all hoped,” said Cpl. Sandy Matharu, investigation lead with the Northeast Nova RCMP Major Crime Unit.

Cadaver dogs brought in

In September, two RCMP police dogs specifically trained in the detection of human remains were brought in to search a 40-kilometre area near the home.

It marked the first time cadaver dogs were used in the investigation.

Earlier this month, RCMP said those dogs did not find any remains.

“The dogs are highly trained to detect and indicate the scent of human remains, therefore, if the dogs did not alert their handlers, it suggests the dogs were never in the presence of human remains odour,” said Staff Sgt. Stephen Pike with RCMP Police Dog Services.

“However, this doesn’t definitively rule out the presence of remains in the areas that were searched. It means either the odour is there and couldn’t be detected or the odour isn’t there.”

RCMP said that their Northeast Nova Major Crime Unit is still following up and assessing more than 860 tips, 8,060 video files and forensic testing.

Mother’s statement

Brooks-Murray told Global News in the days after the children’s disappearance she was advised by police not to speak to media.

A volunteer missing persons group, Please Bring Me Home, announced in mid-October it was joining the search for the siblings, and issued a statement on behalf of Brooks-Murray.

In the statement, she writes, “I will never stop searching for my children until they are found and brought home safe and sound. Someone, somewhere knows something so please bring my babies home.”

Nick Oldrieve, the co-founder of the not-for-profit group, said their goal was to “shake the tree” when it comes to the investigation.

“Maybe it implores somebody to send in a tip if they know something … or the search efforts continue and they’re in those woods,” he said.

Stepfather says he believes ‘they’re not in the woods’

At a vigil Oct. 29 to mark Jack’s fifth birthday, his stepfather said he no longer believes the children are in the woods near the home.

“I believe at this point in the case that they’re not in the woods and they didn’t wander into the woods,” Martell said.

He said in light of all the searches and efforts, it doesn’t seem feasible the children are in that area.

He also vowed to keep speaking out and updating the public on the case despite accusations and online rumours.

“I just think with all the accusations and allegations thrown out there and people don’t see me as … the most liked person, I guess. Hatred runs wild and speculations run wild against me,” he said.

“Speculations run wild. But I’d like everybody to know that I’m working with (the RCMP’s) major crimes (unit) almost every day, just trying to figure stuff out.”