Gerald Foisey and Shirley Rosette of 100 Mile House are shown in this undated handout photo. THE CANADIAN PRESS/HO

VANCOUVER - The sinking of the Queen of the North passenger ferry off British Columbia's northern coast is a story made up of many chapters.

There is the tragedy of two missing passengers, Gerald Foisy and Shirley Rosette, who vanished the night the ferry sank seven years ago, and the mystery of what happened to them. Each left behind children, families, and their own struggles that were detailed and catalogued at the trial of one of the ship's crew.

There are dramatic tales of survival. The cleaner who was trapped in her room as it filled with water, escaping with only seconds to spare. The passengers who bobbed in life rafts in the darkness, cold and wet, as they watched the ferry slip below the water. The nearby fishermen who rushed to the scene to help.

And there are the personal transgressions of Karl Lilgert, charged with criminal negligence causing death, and his former lover, Karen Briker, whose illicit affair was laid bare at the trial. The pair was on the bridge when the ship struck a remote island, ripping apart the ferry's hull, letting endless speculation, rumours and innuendo spill out.

Those chapters will be stitched together starting Tuesday, when the Crown and defence present their closing arguments to the jury as Lilgert's trial nears its conclusion.

The Queen of the North was on an overnight voyage heading south from Prince Rupert, B.C., in the early hours of March 22, 2006, when the ship missed a scheduled turn and sailed into Gil Island. A frantic rescue saved the lives of 99 passengers and crew, but Foisy and Rosette were presumed drowned.

The only two people who know exactly what happened on the bridge that night — Briker and Lilgert — each testified at the trial, but neither was able to explain why an otherwise routine sailing turned catastrophic.

They each testified Lilgert was busy navigating the ship when, seemingly out of nowhere, they could see treetops from Gil Island through the window. They also insisted their affair, which ended several weeks earlier after both of their spouses caught wind of it, had nothing to do with what happened.

Lilgert said he was doing everything he could to navigate the ship, watching the radar and ordering course corrections to ensure the ferry kept a safe distance from the island and from two other boats he believed were in the area.

But he could not — or would not — explain why the ferry was so far off course when it slammed into the island.

"I've been searching for that explanation for seven years," Lilgert told the jury last week during four days of testimony.

"Today, I still haven't got an explanation."

Much of the case will come down to whether the members of the jury believe Lilgert, and the Crown will tell them they should not.

During Lilgert's testimony, a Crown prosecutor accused him of lying. Michel Huot suggested Lilgert fabricated his entire story to cover up for the fact that he was distracted by Briker — either because the pair was having sex or having an argument about their recent break up. The possibility that Lilgert and Briker were having sex has been a persistent rumour that has hung over the Queen of the North sinking for years.

Lilgert denied there was anything happening between himself and Briker, sexual or otherwise, that played any role in the sinking.

On the other hand, the defence will tell the jury Lilgert was a competent and experienced mariner whose work was hampered by unreliable equipment, poor training, bad weather and inadequate staffing policies within BC Ferries, the former Crown corporation that runs the province's ferries.

The sinking was caused by "the system," Lilgert's lawyer said in his opening statement, foreshadowing a theme that is expected to figure prominently in his closing submissions.

The trial heard from dozens of witnesses, including survivors, fishermen involved in the rescue, marine experts and family members of Foisy and Rosette.

The Crown presented data from the ship's electronic chart system, referred to as the equivalent of a "black box," that indicated the ferry continued in a straight line after it missed the initial turn, with no course changes before the collision.

A marine expert described Lilgert's failure to steer the ship away from the island as an "extreme, catastrophic dereliction" of duty.

Children and other relatives of Foisy and Rosette took the stand earlier this month, telling the jury about the two missing passengers who are at the heart of the case.

Foisy and Rosette had lived in 108 Mile House in B.C.'s Cariboo region, though they had recently moved into an apartment in nearby 100 Mile House.

The couple met several years earlier. Foisy had divorced his previous wife, and Rosette's husband died in a fishing accident in 2003. They each had two children.

The trial heard Foisy had a difficult time after his divorce and Rosette struggled after her husband's death.

Both were taking antidepressant medication and Foisy had a drinking problem. The couple had wine with dinner in the hours before the sinking, the trial heard, which prompted questions about whether the combination of their antidepressants and alcohol could have caused drowsiness.

The closing arguments are scheduled for Tuesday and Wednesday. The next step will be for Judge Sunni Stromberg-Stein to deliver her instructions to the jury, after which the jury will begin its deliberations.

Lilgert pleaded not guilty to two counts of criminal negligence causing death.

News from © The Canadian Press, 2013