It is perhaps the most pressing question in a tragedy that is filled with questions.
Where is Lisa Gibson?
The 32-year-old mother disappeared Wednesday morning after her two children -- Anna, 2, and Nicholas, three months -- were found drowned in the bathtub in their Westwood home. Her husband, Brian Gibson was not home at the time.
The Free Press has spoken with several Winnipeg police officers -- both involved in the investigation and watching from the sidelines -- to get a sense of the most plausible scenarios surrounding the case.
Four theories are being explored to varying degrees.
1. Lisa Gibson ended her life in the Assiniboine River shortly after her two children were drowned in the bathtub
Privately, police speculate this is what happened following the discovery of Gibson's two children Wednesday morning in a bathtub in their Westwood home.
"That was the first thought, that she was headed to the river," a cop working the case told the Free Press.
This belief began to play out publicly Friday when members of the police dive team took to the fast-moving water of the Assiniboine a short distance from Gibson's home.
"We felt it was time to open up to the possibility," said police spokesman Const. Eric Hofley. Sources told the Free Press the dive wasn't based on a confirmed sighting of Gibson at the riverbank at any time.
There are many reasons police believe this is the most likely outcome to this case.
First, Gibson had recently been diagnosed with postpartum depression. She saw a doctor last week and was given medication.
Second, Gibson had quick access to the river via a path in a nearby park.
Third, Gibson was last seen wearing just a tank top and pyjamas, indicating she had a fractured state of mind. And she was on foot, indicating no real ability to go far without being noticed.
"You figure it was an emotional reaction, things have come to a head and now she's looking at the stark reality. A lot of people (in cases of suspected homicide) think suicide. They think their life is over when they commit the ultimate crime," said James Jewell, a retired homicide detective.
Two other officers told the Free Press Friday bodies will typically begin to surface between two to five days after they go under water, meaning investigators are entering a critical phase this weekend. However, there is so much debris in the murky river that a body could easily become snagged on it.
"You could also be found downstream, even as much as several kilometres," said one police expert. What makes this case unique is there is no confirmed entry point, or time of entry. Divers must move around the water completely blind to what they might find.
"There is no visibility in the water," he said.
2. Lisa Gibson is deceased in another location and has yet to be found
There have been dozens of reported sightings of Gibson, including some made to RCMP from outside the city. Police have yet to confirm any of them are legitimate, but sources say this information has opened up the possibility Gibson went some distance from her home.
Hofley said investigators were reviewing surveillance video taken from neighbouring businesses. They hope this might be able to provide a timeline of her route, if there is one.
Police have also conducted door-to-door searches and viewed yards of neighbouring homes on the chance Gibson might be found.
As of Friday, there was no sign of her.
Sources say no suicide note has been found.
"You figure, given the neighbourhood, that if people saw someone like her in obvious distress you'd get a lot of calls about it. But that hasn't happened," one officer said.
But police haven't discounted the possibility she died at another location and her body hasn't been found yet. They urge Winnipeggers to closely check their property and report anything that might seem "off."
3. Lisa Gibson is alive and currently hiding out in the city, perhaps with loved ones
This is the scenario those involved in the case hope for. But, sources say it's increasingly unlikely this will be the outcome.
Since Wednesday, police have been building a profile of Gibson, including a list of her friends, where she liked to visit and her daily routines. Police have also interviewed her many loved ones on the off chance she's taken shelter with one of them.
"You do wonder if she's being harboured, and maybe she'll suddenly turn up and walk into a police station," said Jewell. "You can't ignore these kind of possibilities."
Hofley said he's "not aware" of Gibson taking any personal items, such as a purse, wallet or bank cards, which could help facilitate a getaway. Jewell, and other police sources, said the absence of any money trail is a telling sign.
Still, police haven't closed the door on the possibility Gibson is alive.
"I can't reiterate enough, our hope that we locate her safely and are able to speak to her," Hofley said.
4. Lisa Gibson is alive and has fled the jurisdiction
It's the most unlikely scenario, but that hasn't stopped police from putting officials at the airport, bus depot and border on notice to keep their eyes open. RCMP have also been notified.
"I don't think she has the state of mind to make an elaborate getaway," one officer involved in the case said. "That would be the most shocking thing, if that were found to be the case that she fled."
"There seems to be no indication of a plan here," another officer added.
However, police say they are keeping all possibilities open.
"We can't discount any theory," Hofley said.